Explore every episode of the podcast The Science, Microbes & Health Podcast
| Title | Pub. Date | Duration | |
|---|---|---|---|
| An overview of the DOMINO project, with Prof. Orla O’Sullivan | 29 Oct 2026 | 00:29:45 | |
This episode features Prof. Orla O’Sullivan from Teagasc Food Research Centre, APC Microbiome Ireland and University College Cork, speaking about the DOMINO Horizon Europe project, which focuses on fermented foods. The project is led by the French Institute for Agriculture, Food and the Environment (INRAE), with partners across 10 countries. The goals of DOMINO are to investigate health benefits for milk kefir in both health and disease, and to design novel plant-based fermented food products. Kefir was chosen because one particular kefir developed in Canada showed early evidence of health benefits, and had potential to be reproducible and controlled. In the DOMINO clinical trials, various endpoints were studied, including people’s lipid profiles, microbiomes, metabolomic profiles, and weight changes. ‘Living Labs’, or stakeholder groups, are an important part of the project. Discussions with consumers and other stakeholders were used to co-design the novel fermented foods so that the science could remain relevant and address any concerns by these groups. A major challenge in the field of fermented foods is to establish controlled and stable fermented foods that can be used as interventions. Clear scientific evidence on fermented foods’ health benefits in humans is needed. DOMINO is looking at 6 different plant-based fermented products and doing case studies to help develop these foods. Prof. O’Sullivan says additional multi-disciplinary efforts are crucial, going forward, for creating controlled fermented foods that provide health benefits to the consumer. Episode abbreviations and links:
Prof. Orla O’Sullivan is a Principal Research Officer in Teagasc Food Research Centre, Ireland and Principal Investigator with VistaMilk and APC Microbiome Ireland, Research Ireland Centres). She holds an Adjunct professorship with the School of Cell Biology and Biochemistry, University College Cork. Orla has a H-Index of 74 with over 31000 citations leading to a list as a Clarivate Analytics Highly Cited Researcher. In 2019, she was awarded the highly prestigious SFI Early Career Researcher of the Year. Her research focuses on elucidating the microbiome from various environments including human gut and lung, soil, rumen and food. Currently she is vice Coordinator on the Horizon Europe project DOMINO which aims to assign health benefits to milk kefir and design novel plant based fermented foods. | |||
| Highlights of the HealthFerm initiative, with Prof. Christophe Courtin | 24 Sep 2026 | 00:29:45 | |
This episode features Prof. Christophe Courtin from KU Leuven (Belgium), speaking about the European HealthFerm initiative. HealthFerm began in September 2022 and brought together multiple institutions and companies to advance the project with a grant of 30 million Euros. The main aim of the project was to improve public acceptance of plant-based foods through fermentation. A citizen science component of the project involved gathering fermented food samples from all over Europe, both home fermenters and small bakeries, to analyze the microorganisms. The researchers received over 650 sourdough starter samples and around 200 other fermented foods samples; from these, they identified some new species that still need to be named. Another part of the project involved a clinical trial on how the body responds if short-chain fatty acids are released in the small intestine versus in the colon. They found that small intestinal release increased GLP-1 levels more than PYY; the opposite happened with colonic release. Another study in the project compared oat to fermented oat, and found that the fermentation changed the fiber (degree of polymerization), and also led to positive health effects. Prof. Courtin says the potential for future research in this area is to find out how to add nutritional benefits through fermentation (for example, vitamin B12 in plant-based foods), as well as how to change the fiber profile in a food to yield specific health benefits. Episode abbreviations and links:
Prof. Christophe Courtin is a full professor at the Laboratory of Food Chemistry and Biochemistry at KU Leuven, Belgium. His research focuses on cereal constituents, the enzymes that degrade them and microorganisms in cereal processing. The emphasis is on a basic understanding of the structure and properties of these constituents as well as on their technological and health functionality in cereal-based processes and products. Expertise and an extensive network in this area have been built up through over 40 supervised PhDs, projects and national and international collaborations. He coordinates HealthFerm, a 23 partner Horizon Europe project. He is author of 380 peer-reviewed papers (WoS h-index: 74) and inventor on 12 patent families. Recent awards are the Harald Perten Prize (ICC, 2021) and the Belfort Lecture Award (Whistler Centre for Carbohydrate Research, Purdue University, 2023). | |||
| Epidemiological insights on the gut microbiota in colorectal cancer, with Dr. Mingyang Song ScD | 04 Sep 2026 | 00:29:45 | |
This episode features Dr. Mingyang Song ScD from Harvard University (USA), speaking about epidemiological evidence connecting the gut microbiota to colorectal cancer (CRC) and whether the evidence supports the gut microbiota as a ‘driver’ or a ‘passenger. Dr. Song explains how he and colleagues studied the gut microbiome in a subset of people from the Nurses’ Health Study. It’s known that adenoma removal reduces CRC risk, but doesn’t eliminate it. Does the gut microbiome contribute to this remaining risk? The researchers found that many years after adenoma removal, individuals had a different gut microbiota compared with healthy controls, indicating that the microbiome profile is not fully restored by adenoma removal. People with past adenoma removal had a gut microbiota that overlapped with that of current CRC patients, with the caveat that lots of heterogeneity was observed. Diet and lifestyle also correlate with both CRC development and gut microbiome composition, with some of the main factors reducing CRC risk being dietary fiber, fruits, vegetables, whole grains, and calcium. These and other healthy lifestyle factors were associated with fewer of the gut microbial members typically seen in CRC. Next, prospective studies are needed to determine whether gut microbiota changes truly precede CRC and independently contribute to risk. This line of research could also lead to a more tailored approach to CRC screening, with risk factors being taken into account. Episode abbreviations and links:
Mingyang Song, MBBS, ScD is Associate Professor of Clinical Epidemiology and Nutrition and Faculty Director of Graduate Studies in the Department of Epidemiology at the Harvard T.H. Chan School of Public Health, and Associate Professor of Medicine at Harvard Medical School. His research focuses on two complementary areas: (1) integrating large-scale prospective cohort studies with biomarker-driven clinical trials to develop nutrition- and microbiome-based approaches for cancer prevention and treatment; and (2) combining electronic health records with molecular and spatial profiling to enable precision risk prediction and personalized colonoscopy screening and surveillance. Dr. Song has received numerous honors, including the NextGen Star Award from the American Association for Cancer Research (AACR) and the Young Investigator Award from the American Gastroenterological Association (AGA). He currently serves as the Vice Chair of the Obesity, Metabolism and Nutrition (OMN) Section at AGA, Statistics Associate Editor of Gut, Associate Editor of the Journal of the National Cancer Institute (JNCI), and Editor of the European Journal of Epidemiology. | |||
| Molecular mechanisms of colorectal cancer development, with Prof. Alberto Martin PhD | 20 Aug 2026 | 00:29:45 | |
This episode features Prof. Alberto Martin from University of Toronto (Canada), speaking about the molecular mechanisms by which certain bacteria – namely, pks+ E. coli – influence colorectal cancer development. pks+ E. coli secretes a toxin that causes DNA damage; likely its purpose is to keep other microorganisms in check, but it appears to have the effect of promoting colorectal cancer. A low-fiber diet starves mucolytic bacteria, reducing the mucus layer in the gut and allowing pks+ E. coli to come into contact with the colonic epithelial cells, where they secrete the toxin that causes DNA damage. Gut inflammation also factors in, because these bacteria thrive in an inflammatory environment. Interestingly, in looking at the geographic distribution of this microorganism in people around the world, its presence correlates with colorectal cancer rates. Prof. Martin’s lab has clinical trials planned to explore this connection, and other groups are looking at therapies to reduce this microorganism in the gut. Episode abbreviations and links:
Dr. Martin is a Professor and Sanofi Pasteur Chair in Human Immunology in the Department of Immunology at the University of Toronto. He completed his B.Sc. degree at McGill University, and his PhD degree in the Department of Immunology at the University of Toronto. He then pursued post-doctoral training at Albert Einstein College of Medicine in New York, U.S.A., with Dr. Matthew Scharff, focusing on characterizing the molecular mechanisms of antibody responses, specifically somatic hypermutation and class switch recombination, which are two processes that are central to the efficient neutralization of pathogens and toxins. In 2003, he was recruited as a faculty member to the Department of Immunology at the University of Toronto. Dr. Martin’s research program is devoted to understanding the role of genes, their interaction with the environment, and their impact on immunity and pathological conditions, including cancer. His main interest is on antibody production, on how high-affinity antibodies are generated, and how antibodies of different classes are produced. Both of these processes are necessary for an efficient antibody response. Dr. Martin is also investigating the role of the gut microbiota in the etiology of colon cancer and has characterizing the role of diet in modulating the cancer causing effects of specific pathobionts. His lab is also investigating the role of a new gene and how it promotes inflammatory bowel disease (IBD). This work highlights the metabolic effects of the skeletal muscle in supporting a metabolically taxing inflammatory process such as IBD. | |||
| Gut microbiome signatures of colorectal cancer, with Dr. Georg Zeller PhD | 07 Aug 2026 | 00:29:45 | |
This episode features Dr. Georg Zeller PhD from Leiden University Medical Center (the Netherlands), speaking about gut microbiome signatures of colorectal cancer across global populations. An early study Dr. Zeller completed in Peer Bork’s lab suggested that the gut microbiomes of people with colorectal cancer are distinct from controls. This signature, as well as work on the tumor microbiome, all pointed toward Fusobacterium as particularly important. Subsequent studies exploring this idea show wide variation in geography and methods. Accounting for these factors, meta-analyses have confirmed several gut microbiome characteristics that are enriched in colorectal cancer across the global population. Dr. Zeller was interested to see that bile acid metabolism is consistently enriched in the cancer metagenome. The taxonomic profile, however, appears better than the functional profile in distinguishing colorectal cancer from control samples. He emphasizes the importance of linking his insights from bioinformatic efforts to the mechanistic work being done. Initially he was hopeful that a gut microbiome diagnostic could be developed, but currently the highest achievable AUC for the classification models is around 0.85 or 0.9, which may not be adequate for enhancing current clinical tools. The possibility remains for a gut microbiome test to complement existing diagnostics. The most promising area may be targeted gut microbiome modulation for prevention of colorectal cancer, perhaps through diet. His group is also exploring the gut microbiome for early diagnosis of pancreatic cancer, possibly by combining fecal markers with other diagnostic tools. Episode links:
Georg Zeller studied Bioinformatics (major in Computer Science) at the Universities of Tübingen (DE) and Uppsala (SE). In 2010 he obtained a PhD from the University of Tübingen (DE) for work performed at the Max Planck Institutes there. Afterwards he joined Peer Bork’s group at EMBL Heidelberg (DE) as a postdoctoral researcher. From 2015 to 2024 he was an independent Team Leader establishing his microbiome research group at EMBL. In 2023 he was appointed as Associated Professor (promoted to full professor in 2025) in the newly formed Leiden University Center for Infectious Diseases (LUCID) at the Leiden University Medical Center (LUMC, NL) to head the Microbiome Systems Biology group.
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| Biofilms and specific bacteria in colorectal cancer development, with Prof. Cynthia L. Sears, MD | 25 Jul 2026 | 00:29:45 | |
This episode features Prof. Cynthia L. Sears, MD from the Johns Hopkins University School of Medicine and the Bloomberg School of Public Health (USA), speaking about both biofilms and specific gut microorganisms that may contribute to colorectal cancer development. Initially, Prof. Sears became interested in enterotoxigenic Bacteroides fragilis in connection with colon cancer. Further investigation found complex biofilms with multiple bacteria fixed to the surface of the tumor. The biofilms were shown to be oncogenic, and they reassembled very quickly after antibiotic treatment. Interestingly, the biofilms were found to have C. difficile. A subset of the biofilms have a dominant amount of Fusobacterium, and the latest work shows that these bacteria are associated with advancing cancer, stage 2 or beyond. These bacteria and/or biofilms don’t necessarily trigger the onset of mutations that lead to colon cancer, but they accelerate tumor growth. Over time, the gut microbiota may be perturbed in various ways (including by antibiotics), allowing the organisms to create a niche for themselves that ultimately harms the colonic epithelial cells. Prof. Sears is optimistic about prevention strategies for colorectal cancer, such as a tool that helps predict risk in younger populations. Targeted prebiotics, too, show promise for encouraging the growth of beneficial bacteria that prevent the oncogenic species from finding a niche. Episode abbreviations and links:
Cynthia L. Sears, M.D. is Professor of Medicine, Oncology and Molecular Microbiology and Immunology at the Johns Hopkins University School of Medicine and the Bloomberg School of Public Health. Through her work as an infectious diseases specialist, she studies how bacteria and the microbiome impact gut diseases, particularly human colon cancer. She has long been an active member of the Infectious Diseases Society of America (IDSA), serving as President of IDSA in 2019, is an AAAS Fellow and is currently Editor-in-Chief of The Journal of Infectious Diseases, the flagship journal of the IDSA. | |||
| The early life gut microbiota in the developmental origins of health & disease, with Dr. Anne Salonen PhD | 07 Jul 2026 | 00:29:45 | |
This episode features Dr. Anne Salonen PhD from University of Helsinki (Finland) speaking about her studies on the gut microbiota in early life and how it relates to health and disease. She noted that while mode of delivery (C-section or vaginal birth) is the largest factor affecting microbiota composition for the first weeks and months of life, the immunological and functional microbiota consequences of this are still unknown. However, there appear to be ‘windows of opportunity’ in which microorganisms can influence the development of the immune system, which have lasting consequences for health. Dr. Salonen describes her Finnish HELMi birth cohort, a longitudinal, prospective general population birth cohort, set up to identify factors that modify the gut microbiota and how they relate to child health and wellbeing. Children from 1055 families were sampled frequently in the first 2 years of life and followed as they grew older. The findings confirmed that early-life microbiota composition was a risk factor (among others) for certain diseases as the children developed. Prof. Salonen also described her study on inoculating the infant gut with maternal gut microbiota via milk feeding after C-section birth. They found, in an initial small study, that the gut microbiota of the infants became similar to vaginally born infants. She sees this type of inoculation as a research tool, and says the field will progress toward standardized, reproducible interventions in this area. Episode abbreviations and links:
Dr. Anne Salonen is a principal investigator and director of the Human Microbiome Research Program at the Medical Faculty, University of Helsinki. Her research is focused on the intestinal microbiota in health and disease, especially in early life and in relation to diet. Dr. Salonen is a PI of the Finnish Health and Early Life Microbiota (HELMI) birth cohort and involved in maternal fecal microbiota transplantation studies in C-section infants. She is the coordinator of the European Innovation Council Pathfinder project on gut microbiota in precision nutrition (fibrematch.eu). Dr. Salonen’s research also entails female reproductive tract microbiota in relation to reproductive outcomes and Human Papilloma Virus (HPV) infection. Research methodology in Salonen laboratory ranges from NGS and other omics technologies to culture-based microbiology of anaerobes, including application and development of bioinformatic tools for microbiome research. More on our research at https://www.helsinki.fi/en/researchgroups/microbes-inside. | |||
| Factors affecting infant gut microbiota development, with Prof. Christopher Stewart PhD | 18 Jun 2026 | 00:29:45 | |
This episode features Prof. Christopher Stewart PhD from Newcastle University (UK), speaking about the factors affecting gut microbiota development in both non-preterm and preterm infants. Prof. Stewart started in the field of environmental microbial ecology and then came to work in human microbiome research. He was involved in the landmark TEDDY study, which aimed to find gut microbial markers of type 1 diabetes (T1D). Although no microbial triggers of T1D were identified, the study found a number of factors that impact gut microbiome development: for example, sex, geographical location, and living with furry animals. Still, most of the variation seen in the infant gut microbiota remains unaccounted for. He noted that infants are exposed to both vaginal and gastrointestinal microorganisms during vaginal birth. In C-section-born infants, seeding of the maternal vaginal and gut microbiota may be promising, but current methods are imprecise and safety has not been established. Furthermore, diet takes over as a primary driver of gut microbiota a few weeks after birth. Prof. Stewart talked about human milk oligosaccharides (HMOs), well known to be utilized by bifidobacteria in the infant gut. His lab recently published the surprising finding that Clostridium species can also utilize HMOs – and while at first this was thought to be detrimental for the infant, further investigation showed that the HMO-utilizing Clostridium may lack the genes for producing specific toxins and end up being protective for the infant gut. Together, the microbial community in the gut may use the full suite of HMO substrates reaching the infant gut. Preterm infants are a population that needs more attention. Antibiotics affect their gut microbiomes – often in a negative way, but for the overall benefit of the baby. His lab is currently funded to study how probiotics affect the preterm infant gut microbiota, and to find strategies for more personalized approaches to administering probiotics in this population. Episode abbreviations and links:
Professor Christopher Stewart is an internationally recognised leader in human microbiome research. He earned his PhD in Microbial Ecology from Northumbria University (UK), followed by postdoctoral training at Baylor College of Medicine (Houston, Texas), before establishing his research group at Newcastle University in 2018. His pioneering work focuses on microbial-host interactions in the gut, particularly in infants born extremely premature (<32 weeks gestation). His lab integrates multi-omic analyses of clinical samples with experimental microbiology and organoid co-culture systems to uncover mechanisms of microbial influence on early-life development. More recently, he has expanded his research to support a UK-wide initiative investigating microbiome-based predictors of therapeutic response in adult inflammatory bowel disease. Professor Stewart has published over 140 peer-reviewed articles in leading journals, contributing to the discovery of novel biomarkers and targeted microbiome-based interventions. He has received numerous prestigious awards, including the Blavatnik Award for Life Sciences Laureate, the Lister Institute Research Prize, the Microbiology Society Fleming Prize, the NOSTER & Science Microbiome Finalist Prize, the Applied Microbiology International WH Pierce Prize, and the Neonatal Society Rising Star Award. His research has broad implications for understanding diet–microbe–host interactions and improving health across the life course, miology, maternal and child health, and microbiome science, with a particular emphasis on the effects of vaginal microbiota transfer (VMT) on the microbiota composition and health outcomes of cesarean-delivered infants. | |||
| A mechanism linking the newborn skin microbiota to neurodevelopment, with Prof. Rihua Xie and Dr. Yuhang Zhang | 26 May 2026 | 00:29:45 | |
This episode features Prof. Rihua Xie from Guangdong Medical University (China) and Dr. Yuhang Zhang from Peking University First Hospital (China), speaking about vaginal microbiota transfer (VMT) and how it may affect neurodevelopment in newborn infants born by Cesarean section. Compared with vaginally delivered infants, C-section delivered infants have altered microbial exposures. VMT has been proposed as a way to ‘restore’ the microbiota of these infants to more closely resemble that of vaginally-born infants. A recent study by Prof. Xie and Dr. Zhang showed that the order and timing of early microbial colonization of the infant is important. They found that VMT could establish a vaginal-like skin microbiota in infants born by C-section, with two particular bacterial species that were higher after VMT. These two species led to the production of metabolites that combined on the newborn’s skin to synthesize an important lipid, which was positively correlated with neurodevelopment scores at three and six months. Subsequent mouse model work showed how this lipid could reach the brain. In the future, safety and standardization of VMT will be important priorities in this research area. Prof. Xie and Dr. Zhang emphasized that their work needs to be replicated in larger cohorts, with the eventual goal of engineering bacteria to create a probiotic intervention that delivers neurodevelopmental benefits to C-section born infants. Episode abbreviations and links:
Dr. Ri-hua Xie (RN, PhD, FAAN) is Professor, Principal Investigator, and Chief Nurse at the School of Nursing, Southern Medical University, and the Affiliated Foshan Women and Children Hospital, Guangdong Medical University, China. Dr. Xie is widely recognized for her expertise in maternal and infant health as a clinician, researcher, and supervisor. She has published more than 90 peer-reviewed papers and 11 nursing textbooks and has received 12 competitive research grants from institutions in China and Canada. In addition to her academic work, Dr. Xie is actively engaged in community and public health service, including breastfeeding promotion and frontline support during the COVID-19 pandemic. Her research focuses on perinatal epidemiology, maternal and child health, and microbiome science, with a particular emphasis on the effects of vaginal microbiota transfer (VMT) on the microbiota composition and health outcomes of cesarean-delivered infants. About Dr. Yuhang Zhang:Yuhang Zhang, PhD in Pharmacology, is an Associate Professor and Principal Investigator at Peking University First Hospital. He received his MD-PhD from Capital Medical University and was a visiting scholar at McGill University, Canada. Dr. Zhang’s research focuses on gut microbiome, probiotics, and microbial metabolism in metabolic diseases, who has published over 20 peer‑reviewed papers as first or corresponding author in journals including Gastroenterology, Journal of Hepatology, and Nature Communications, cited >1,000 times. He has led 9 grants, including the National Natural Science Foundation of China, who was selected for the Beijing Association for Science and Technology Young Talent Program (2022) and the China Association for Science and Technology Young Talent Program (2025). The research of Dr. Zhang focuses on the integrated systems pharmacology, multiomics and microbiome‑host interactions to develop precision medicine. | |||
| Gut microbiota development in preterm and non-preterm infants, with Dr. Marie-Claire Arrieta PhD | 08 May 2026 | 00:29:45 | |
This episode features Dr. Marie-Claire Arrieta PhD from the University of Calgary (Canada), speaking about development of the early life gut microbiome, both in preterm and non-preterm infants. Across the field, it has been established that the early days and months of an infant’s life are very determinant of immune system development as well as chronic disease later in life. In this period, environmental cues are important, with some of these cues coming from the gut microbiome – both bacteria and fungi. Preterm infants show a very different gut microbiome than non-preterm infants. Ample evidence shows probiotics given to preterm infants can bring clinical benefits such as a reduced risk of necrotizing enterocolitis, but this is separate from investigations into the infants’ gut microbiomes. Dr. Arrieta’s work has shown that probiotics can guide the gut ecosystem of preterm infants toward approximating the non-preterm gut microbiome. One gap in the research is to know more about the effects of specific strains; their work found that although bifidobacteria were more effective at colonizing in the gut, lactobacilli drove some aspects of microbiota maturation. Dr. Arrieta speculates that the case for probiotic use for preterm infants will become stronger as trials increasingly focus on health outcomes not just during the neonatal intensive care unit stay, but also later in life. The CHILD Cohort Study has found that overall in healthy infants, different patterns of gut microbiome and immune development can lead to the appearance of diseases later in life. The latest insight is that disease is linked not to specific microbes or metabolites, but to the pace of gut microbiome development. Misalignment of gut microbiome development (too early or too late) with stages of immune development is associated with later emergence of allergic disease. Several factors such as C-section birth and antibiotics may contribute to this misalignment, but breastfeeding seems to mitigate it. Dr. Arrieta has an ongoing longitudinal study on the early life microbiota and disease associations in preterm and non-preterm infants that is likely to reveal more details. Episode abbreviations and links:
Dr. Marie-Claire Arrieta is a Professor and Research Excellence Chair at the Cumming School of Medicine, University of Calgary. Her research examines interactions between the early-life gut microbiome and infant development. Her program integrates clinical and experimental approaches to uncover mechanisms of host–microbiome communication. Her work, published in leading journals, has accumulated over 12,000 citations. She has presented her research internationally through more than 120 invited talks to scientific, medical and public audiences. A dedicated mentor, she has supervised over 45 undergraduate, medical, PhD, and postdoctoral trainees. Her contributions have been recognized with the CIHR-SickKids New Investigator Award, the Killam Emerging Research Leader Award, and election to the College of New Scholars of the Royal Society of Canada. Dr. Arrieta is co-author of the best-selling public book, Let Them Eat Dirt, and is involved in several science communication initiatives. | |||
| Toward skin microbiome interventions for anti-aging and wound healing, with Prof. Hariom Yadav PhD | 23 Apr 2026 | 00:25:32 | |
This episode features Prof. Hariom Yadav PhD, from the University of South Florida (USA), speaking about the skin microbiome and potential interventions for anti-aging and wound healing. Prof. Yadav noted that humans have a stable (core) microbiome on the surface of skin cells, plus a transient microbiome that depends on recent exposures. The skin microbiome constantly changes through the lifespan, and in aging, many skin conditions are correlated with the microbiome. Animal studies show a causal component of the microbiome in some of these conditions. However, because of the large skin microbiome differences from person to person and in narrow age groups, technologies or products may have to be designed in a personalized way. Prof. Yadav’s lab conducted experiments with lactobacilli and found strain-dependent effects of probiotics on anti-aging, and for some strains these effects persisted when the inactivated bacteria (postbiotics) were used. The postbiotics have commercial advantages over probiotics in this area of health. Prof. Yadav described an application in wound healing, building on the idea that microbial stimulation promotes natural skin cell growth and more fibroblasts. A standard treatment for wound healing is effective but may lead to scarring; the postbiotic treatment leaves less scarring. The efficacy of the postbiotic occurs because inactivated bacteria still give growth-promoting signals to the skin cells. Applying metabolites directly may not be as effective because bacterial cells or extracts work on host cells, which changes the skin environment and further supports positive skin microbiome changes. Episode abbreviations and links:
About Prof. Hariom Yadav PhD: Dr. Hariom Yadav is a Professor at the University of South Florida and Director of the USF Center for Microbiome Research, and co-founder of Postbiotics Inc (www.postbioticsinc.com) and MusB Research (www.musbhealth.com). With over 25 years of experience, he specializes in microbiome science, biotics, nutrition, longevity, and natural products for optimal wellness. He has authored 200+ peer-reviewed publications, holds/filed 7 patents, mentored over 80 scientists, and has successfully translated multiple innovations into commercially viable products. Dr. Yadav works closely with industry partners to accelerate product development—from discovery and mechanistic validation to clinical trials and regulatory readiness. He leads global collaborative efforts, including the MELLOW (Multi-continental Evidence of Longevity and Lifestyle for Optimal Wellness) consortium, a unique platform for scalable, multi-region clinical validation. His integrated approach enables companies to build scientifically robust, market-ready products with strong differentiation and credibility. He is committed to moving science from bench to market, delivering measurable health impact and commercial success. | |||
| Inflammatory microbes on the skin, with Dr. Nathan Archer PhD | 09 Apr 2026 | 00:29:45 | |
This episode features Dr. Nathan Archer PhD from Johns Hopkins Medicine (USA), speaking about the skin microbiome and particular microorganisms that cause inflammation. The skin is a dynamic organ with the main functions of keeping moisture in and keeping the environment out. Overall, the skin environment is not very welcoming to microorganisms but some have adapted to thrive in the low pH environment. His research has found that certain bacteria that are normally considered commensals can become pathogenic when they start producing specific proteases that instigate inflammation on the skin. Acute inflammation that removes a bacterial exposure from the skin is beneficial, but chronic inflammation can be a major problem. Staphylococcus aureus is a bacterium that predominates in many inflammatory skin diseases and benefits from an inflammatory environment and disruption in the skin barrier; in turn, S. aureus is proinflammatory and uses proteases to drive skin inflammation. His lab is interested in understanding the connection between skin microorganisms and the ‘atopic march’ (progression of allergic diseases, including atopic dermatitis, through infancy and childhood). They found that S. aureus on the skin can exacerbate allergic reactions in the lungs, driving hard-to-treat neutrophilic asthma. His group is contributing to several strategies for preventing / treating skin and allergic diseases, including a vaccine for S. aureus; so far, vaccines against this bacterium have not succeeded because S. aureus has so many tools for avoiding human immune responses. However, a multivalent vaccine targeting multiple toxins that affect the immune system is currently being developed and is in Phase 1 clinical trials. Episode abbreviations and links:
About Dr. Nathan Archer PhD: Dr. Nathan Archer is an Associate Professor at the Johns Hopkins School of Medicine Department of Dermatology. Dr. Archer’s research involves uncovering how skin microbes, especially the major human pathogen Staphylococcus aureus, exacerbate inflammatory skin diseases such atopic dermatitis as well as how host immunity protects against bacterial skin infections. His work involves the incorporation of immunological and “omic” approaches with preclinical models and clinical samples to reveal mechanistic insights with translational relevance to human disease. His long-term research goals are to develop novel host-directed therapies for the treatment of inflammatory skin disorders and skin infections. Dr. Archer has received funding from the NIH as well as from foundation and industry sources, including the Dermatology Foundation, LEO Foundation, and Pfizer. He has been an invited speaker at numerous international and national conferences with a focus on dermatology, immunology, and microbiology. | |||
| The skin microbiome’s role in atopic dermatitis, with Dr. Maria Teresa García-Romero, MD MPH | 25 Mar 2026 | 00:29:45 | |
This episode features Dr. Maria Teresa García-Romero, MD MPH from the National Institute of Pediatrics in Mexico City, talking about the skin microbiome and how it relates to atopic dermatitis. The skin microbiome varies widely at different sites on the body, but in general, increased diversity is associated with healthy skin. In atopic dermatitis, Staphylococcus aureus becomes abundant and skin microbiome diversity decreases, correlating with inflammatory responses. Treatments have the effect of reducing Staphylococcus aureus. These bacteria are now established to have a role in the pathophysiology of the disease. The caution with antibiotic treatment is that a systematic review and meta-analysis from Dr. García-Romero’s group found Staphylococcus aureus isolates from people with atopic dermatitis had suboptimal susceptibility to commonly used antimicrobials, especially in lower middle-income and upper middle-income countries. Mechanistically, Staphylococcus aureus decrease natural antimicrobial molecules in the skin, stimulate the innate immune response, and likely reduce beneficial bacteria. New treatments are urgently needed because atopic dermatitis is very prevalent (affecting 20-30% of the population), with far-reaching effects in children’s and families’ lives. Two ingested probiotics are commercially available for atopic dermatitis, backed by clinical data, whereas topical probiotic treatments require further research. Episode abbreviations and links:
About Dr. Maria Teresa García-Romero: Dr. Maria Teresa García-Romero is a medical doctor graduated from Tec de Monterrey School of Medicine, magna cum laude. She has a Specialty in Dermatology and Diploma in Medical Mycology from UNAM, Mexico City. Dr. García-Romero completed a Fellowship in Pediatric Dermatology at the University of Toronto, and a Master’s degree in Public Health and Quantitative methods of research at Harvard University Chan School of Public Health. She has received meritorious awards including the Mexican Foundation for Health (FUNSALUD), Harvard University Presidential Award, Society for Pediatric Dermatology Fellow Award, among others; and funding for research projects by prestigious international organizations such as MIT (Massachusetts Institute for Technology) seed funds and EB Research Partnership. She is currently an attending physician in the Dermatology Department of the National Institute of Pediatrics in Mexico City and a member of the National System of Researchers level II. She has more than 150 articles published in national and international magazines, supervised multiple postgraduate theses and has presented in multiple forums worldwide. Dr. García-Romero is a member of the Editorial Committee of JAMA Dermatology, Pediatric Dermatology and other high impact journals. Her research interests include the skin microbiome, atopic dermatitis, vascular anomalies and autoimmune disease. | |||
| An introduction to skin microbiome research, with Dr. Aayushi Uberoi PhD | 13 Mar 2026 | 00:29:45 | |
This episode features Dr. Aayushi Uberoi PhD from Washington University in St. Louis (USA), speaking about the skin microbiome and various techniques for studying it. The skin is a reactive interface that protects the body, with the skin on various parts of the body looking very different because of stratifications in the epithelial layers and the local nutritional landscape. The skin microbiome in general is nutrient sparse and varies at different body sites. Research has shown that epithelial development, stratification, and differentiation are altered in the absence of the microbiota, showing the active role of the skin microbiota in regulating skin function. Microbes that inhabit the skin are shown to elicit unique immune responses with systemic effects. Communication between skin microbes and human body cells may be happening via metabolites. When conducting skin microbiome experiments, controls are important; the low biomass samples are susceptible to contamination. In the future, knowing more about the nutritional needs of the skin microbes could help guide the development of prebiotics for skin. Episode abbreviations and links:
About Dr. Aayushi Uberoi PhD: Aayushi Uberoi is an Assistant professor of Pathology & Immunology and Medicine (Dermatology) in Washington University School of Medicine in Saint Louis. Her lab studies the host-microbe-environment interactions in regulating skin barrier. She has studied interactions between microbes and skin since her Ph.D. research on cutaneous papillomaviruses in Dr. Paul Lambert’s lab at the University of Wisconsin-Madison. While traditional studies of infectious skin diseases have typically focused on singular pathogens within the host, skin is colonized by a diverse array of microbes, which likely exert significant influence on epithelial characteristics. Motivated by this question, Aayushi’s postdoctoral research at the University of Pennsylvania in Dr. Elizabeth Grice’s lab explored the role of the commensal microbiome in regulating the function of the cutaneous barrier. In the lab, Aayushi wears several hats such as conducting research, developing protocols and assays, writing, and making sure the lab has fun equipment. Aayushi is a recipient of K99/R00 Pathway to Independence award from National Institute of Arthritis & Musculoskeletal & Skin Diseases (NIAMS/NIH), innovator award from Society of Investigative Dermatology, fellowships from Prevent Cancer Foundation and Dermatology Foundation and a Young Investigator Award from the Wound Healing Society. | |||
| ISAPP’s scientific consensus definition of gut health | 22 Feb 2026 | 00:29:45 | |
This episode features two guests from the ISAPP board of directors who led the recently published consensus definition of gut health: Prof. Maria Marco PhD from UC Davis (USA), and Prof. Eamonn Quigley MD from Houston Methodist Hospital (USA). In the paper, the group defines gut health as: “a state of normal gastrointestinal function without active gastrointestinal disease and gut-related symptoms that affect quality of life”. Gut health is a commonly used term that previously had no scientific definition. Initially the group of experts (both scientists and physicians) that met to discuss it had a lot of skepticism, but they became more enthusiastic and engaged as the discussion proceeded and were finally able to reach consensus. The group identified 6 distinct domains that are encompassed under gut health: gut microbiome, gut barrier, gastrointestinal physiology (primarily intestinal secretions and motility), gut-brain axis, immune function, and metabolism. The group hopes it will provide clarity over time about which aspect(s) of gut health are being assessed in a given study (as it’s not realistic to look at all aspects in a single study). One difficulty is that some of the tests available to measure these domains are quite limited and/or invasive. Nor do consistent correlations exist between symptoms and objective measures of the 6 domains. Determinants of gut health are also discussed in the paper, with diet being important among these. Episode abbreviations and links:
About Prof. Maria Marco PhD: Dr. Maria Marco PhD, is President of ISAPP’s board of directors and Professor in the Department of Food Science and Technology at the University of California, Davis. She earned her PhD in microbiology at the University of California, Berkeley. Prof. Marco started her lactic acid bacteria and gut health laboratory at UC Davis in 2008 and has built an internationally-recognized, NIH, USDA, and NSF funded research program on probiotics, fermented foods, and dietary modulation of the gut microbiome. She is currently a fellow in the American Academy of Microbiology. About Prof. Eamonn Quigley MD: Dr. Eamonn M M Quigley MD FRCP FACP MACG FRCPI MWGO is David M Underwood Chair of Medicine in Digestive Disorders and Chief of the Division of Gastroenterology and Hepatology at Houston Methodist Hospital. A native of Cork, Ireland, he graduated in medicine from University College Cork. He trained in internal medicine in Glasgow, completed a two-year research fellowship at the Mayo Clinic, and training in gastroenterology in Manchester, UK. He joined the University of Nebraska Medical Center in 1986 where he rose to become Chief of Gastroenterology and Hepatology. Returning to Cork in 1998 he served as Dean of the Medical School and a PI at the Alimentary Pharmabiotic Center. He served as president of the American College of Gastroenterology and the WGO and as editor-in-chief of the American Journal of Gastroenterology. | |||
| 2025 highlights in biotic science | 18 Dec 2025 | 00:29:45 | |
This special year-end episode, which covers 2025’s highlights in biotic science, features three of the academic scientists who serve on the ISAPP board of directors: Prof. Maria Marco PhD from University of California, Davis (USA), Prof. Sarah Lebeer PhD from University of Antwerp (Belgium), and Dr. Gabriel Vinderola PhD from National University of Litoral (Argentina). After a brief review of ISAPP’s activities, the host, Prof. Colin Hill PhD from University College Cork (Ireland) asks the three guests about the talks that stood out from the ISAPP annual meeting. The guests cited talks by Prof. Howard Bauchner MD on publishing and the scientific communication ecosystem; Dr. Carolina Tropini PhD on factors affecting the gut microbial environment and engineering gut microbes as biosensors; and Dr. Peijun Tian PhD on a microbial metabolite that can signal to the brain to relieve depression through the gut-brain axis. The guests also described some stand-out papers published this year (linked below). Finally, they discussed how science is informing regulatory issues in different parts of the world, and shared some research from their own labs that they’re particularly excited about. Episode abbreviations and links:
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| Trials on probiotics and prebiotics in infant formula, with Prof. Yvan Vandenplas MD PhD | 04 Dec 2025 | 00:29:45 | |
This episode features Prof. Yvan Vandenplas MD PhD from the University Hospital Brussels and Vrije Universiteit Brussel (Belgium), speaking about the science on probiotics and prebiotics in infant formula. Over the past 20 years in this field, awareness of the importance of the gastrointestinal microbiota has grown, and biotics have been employed to try to shape the gut microbiota of infants formula-fed to resemble that of breastfed infants. In particular, human milk oligosaccharides (HMOs) are prebiotics that are shown to change the microbiota composition, although the clinical benefits of these changes are not yet clear. What clinical benefits are achievable for infants who receive formula with added probiotics or prebiotics? Looking closely at the trials, it’s evident that probiotics and prebiotics are associated with a decrease in infections and antibiotic prescriptions, but researchers need to use these as primary endpoints in their trials to increase the strength of the evidence. In a recent European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) recommendations paper, the probiotic recommendations were challenging because for each specific probiotic intervention the group had difficulty finding two clinical trials with a similar design, limiting their ability to make conclusions. Prof. Vandenplas says more trials need to be done independently to strengthen the evidence. Long-term outcomes from probiotic or prebiotic supplementation in infant formula are possible as well, but much larger longitudinal trials are necessary to establish these outcomes. Episode abbreviations and links:
About Prof. Yvan Vandenplas MD PhD: Yvan Vandenplas did his medical studies at the ”Vrije Universiteit Brussel” (Free University of Brussels) and trained in pediatrics (1981-1986) at the same University. He became Head of the Unit for Pediatric Gastroenterology and Nutrition in 1987 and created the Pediatric Hospital, the KidZ Health Castle, at the University Hospital Brussels (UZ Brussel) of the same university, where he had the Chair of Pediatrics since 1994 up to 2021. He is now Prof. Emeritus and consultant at the same hospital. He is associate editor of Nutrients. | |||
| Dietary management of chronic constipation, with Dr. Eirini Dimidi PhD RD | 26 Nov 2025 | 00:29:45 | |
This episode features Dr. Eirini Dimidi PhD RD from King’s College London (UK), speaking about the recently published British Dietetic Association’s guidelines for dietary management of chronic constipation. Constipation can be a major concern for patients, but evidence around some of the most common dietary recommendations for addressing it has remained unclear. After a thorough review of evidence from randomized, controlled trials, Dr. Dimidi and colleagues found evidence for specific foods / beverages improving certain symptoms of constipation. In addition, some supplements such as psyllium, certain probiotics, and magnesium oxide have evidence for efficacy. A high-fiber diet is a commonly recommended dietary strategy for chronic constipation, but the guideline shows that the evidence to date is insufficient to support this recommendation. (However, a high fiber diet has many other benefits.) Probably the effective foods’ key mechanism of action in relieving symptoms of constipation is the fiber they contain, but future studies need to confirm this. Regarding probiotics, so far the evidence is ambiguous around which strains and which durations of treatment are the most effective so the authors were unable to make a confident conclusion. However, for practical reasons they included the expert opinion that patients should be advised to take a probiotic of their choice for at least 4 weeks in addressing chronic constipation. Episode abbreviations and links:
About Dr. Eirini Dimidi PhD RD: Dr Eirini Dimidi is an Associate Professor in Nutritional Sciences at King’s College London. She is a registered dietitian and nutritionist since 2011, after completing a BSc in Nutrition and Dietetics and a MSc in Clinical and Public Health Nutrition. This was followed by the completion of a PhD from King’s College London where she investigated the effectiveness of probiotics in people with chronic constipation. She is leading research on nutrition-based interventions, including fibre, prebiotics, probiotics, plant foods, and plant-based diets in gut function and dysfunction. She is also investigating the mechanisms through which nutritional interventions may affect immune and mental health via the gut microbiome. Dr Dimidi led the development of the first ever UK national dietary guidelines for the management of chronic constipation, which have been endorsed by the British Dietetic Association. Dr Dimidi was awarded the 2023 Cuthbertson Medal by the Nutrition Society, and the 2022 ISAPP Glenn Gibson Early Career Research Prize for her research on the effect of diet in gut health. She also received the 2021 Rising Star and 2020 Elizabeth Washington awards by the British Dietetic Association. | |||
| How ecological dynamics affect pathogens in the gut, with Prof. Kevin Foster PhD | 07 Nov 2025 | 00:29:45 | |
This episode features Prof. Kevin Foster PhD from University of Oxford (UK), speaking about his lab’s ecological approach to the gut microbiome and efforts to understand and predict dynamics of different species in the microbiome. They also focus on how these ecological dynamics map onto health outcomes, and how they inform interventions. In a 2023 paper, they explored the concept of colonization resistance in the gut, and why certain bacteria or combinations of bacteria are particularly good at preventing pathogens from thriving. Both diversity and composition are important for determining the extent to which a community resists a pathogen. But a microbiome may equally resist a probiotic that’s introduced because the probiotic microorganism doesn’t have access to a unique nutrient. How bacteria interact with each other can help determine resiliency or stability of the microbiome overall. While it’s true that hundreds of species of bacteria exist in the gut, the scale at which the microbes interact locally is much more limited (on the scale of tens of species). Episode abbreviations and links:
About Prof. Kevin Foster PhD: Professor Kevin Foster FRS is the Chair of Microbiology at the Dunn School of Pathology, University of Oxford. Prior to this, he was Professor of Evolutionary Biology in the departments of Biology and Biochemistry at Oxford. Before Oxford, he had a lab at Harvard as a Bauer Fellow in the FAS Center for Systems Biology. He did his undergrad at Cambridge in Natural Sciences and his Ph.D. at the University of Sheffield in evolutionary biology. Professor Foster’s research integrates the traditional fields of ecology and evolution with the latest methods in computation, microbiology, molecular genetics, and the study of the mammalian microbiome. The lab focuses on how bacteria compete and succeed in their communities and seeks to use this to manipulate gut communities for better health. | |||
| Applying the tools of ecology to manage microbiomes in people with cancer, with Dr. Joao Xavier PhD | 25 Oct 2025 | 00:29:45 | |
This episode features Dr. Joao Xavier PhD, a systems biologist from Memorial Sloan Kettering Cancer Center, speaking about the application of ecological principles and tools to individuals being treated for cancer. His lab combines multi-omics profiling with ecological models to generate insights on how microbes interact with each other, for application to clinical risk prediction and microbiota-focused interventions. He has studied individuals receiving bone marrow transplantation, who take antibiotics to prepare for treatment; the antibiotics cause significant gut microbiota shifts and the risk of bloodstream infections increases, so his lab is looking at whether the gut microbiota could mitigate this risk. Currently microbiome monitoring is not being used clinically in patients receiving cancer treatments, but a path exists for gaining the evidence needed to make this feasible and useful. Potentially, microbiome monitoring could allow physicians to move from reactive treatment with antibiotics to proactive intervention that prevents serious infections. Or the clinician could simulate potential treatment scenarios and figure out which one is the most beneficial. Probiotics could be administered to shape the microbiome – but rather than adding microorganisms that may simply be missing, these probiotics would be developed by thinking about the microbiome outcome and how to pressure the ecosystem in a certain direction. Episode abbreviations and links:
About Dr. Joao Xavier PhD: Joao B. Xavier, PhD, is a faculty member in the Program for Computational and Systems Biology at Memorial Sloan Kettering Cancer Center in New York. His lab combines experiments, computational modeling, and clinical data to study how the human microbiota influences cancer treatment outcomes. Dr. Xavier’s work has uncovered links between gut bacteria, immune recovery, and infection risk in patients undergoing intensive therapies such as allogeneic hematopoietic stem cell transplantation. He recently authored a Nature Reviews Clinical Oncology article (2025) proposing “ecological management” of the microbiota in oncology. This approach applies principles of ecosystem management to preserve beneficial microbes, minimize treatment-related damage, and guide precision interventions. He was awarded the 2026 ASM Microbiome Data Prize by the American Society for Microbiology in recognition of these contributions. His group collaborates broadly across clinical and basic sciences to develop microbiota-informed strategies that could improve responses to chemotherapy, immunotherapy, and infection control. | |||
| Insights from evolutionary ecology on microbiome assembly and modulation, with Prof. Jens Walter PhD | 09 Oct 2025 | 00:29:45 | |
This episode features Prof. Jens Walter PhD, a microbial ecologist from University College Cork / APC Microbiome Ireland, explaining how he applies ecological and evolutionary frameworks for the purposes of understanding and modulating microbiomes. Although there appears to be a high amount of stochasticity (or randomness) in microbiomes, stochastic and deterministic elements work together to determine outcomes. Priority effects (based on arrival order of a bacterium or other microorganism) are important, with communities likely taking shape through a combination of priority effects and adaptation to the niche. The potential to modulate the microbiome is high in early life, as there are many ecological possibilities. For established microbiomes (for example, in adults), Prof. Walter’s group has found that diet (for example, the “NiMe” diet they developed) is a possible way to modulate the microbial community, although the effect on the overall ecosystem is small. Nevertheless, dietary modulation may have positive and important effects on host health. Episode abbreviations and links:
About Prof. Jens Walter PhD: Jens Walter serves as the Professor of Ecology, Food, and the Microbiome at University College Cork and the APC Microbiome Ireland. His expertise lies at the interface of evolutionary ecology of the gut microbiome and human nutrition. His research focuses on the evolutionary and ecological processes that have shaped host-microbiome symbiosis and the translation of basic microbiome science into therapeutic and nutritional strategies. Dr. Walter and his collaborators have pioneered the application of ecological theory to elucidate ecological and nutritional factors that shape gut microbiomes and have achieved targeted modulations of microbiomes via dietary strategies and live microbes. Prof. Walter has published >140 peer-reviewed publications (google scholar H-index 69, >23,000 citations) and is a ‘highly cited researcher’ according to the Web of Science group. | |||
| Eco-evolutionary processes and antimicrobial resistance in the urobiome, with Dr. Marjon de Vos PhD | 26 Sep 2025 | 00:27:16 | |
This episode features Dr. Marjon de Vos PhD from the University of Groningen (the Netherlands) speaking about microbial ecology and evolution, and in particular how these affect antimicrobial resistance. She studies the urobiome as well as the factors that contribute to urinary tract infections and successful treatment of these infections with antibiotics. Her lab combines molecular biology techniques with phenotypic and growth measurements, as well as computational modeling. She has found evidence of microbial interactions mediating evolutionary potential of microorganisms – for example, in vitro experiments showed that in the presence of Enterococcus, E. coli speeds up its rate of developing antimicrobial resistance. Thus, interactions within the bacterial ecosystem may affect pathogens’ sensitivity to antimicrobials. Prebiotics are a potential intervention: if bacteria that make a pathogen more susceptible to antimicrobials are already present in the urobiome, their numbers could be enhanced. Probiotics are another possibility. From a One Health perspective, such approaches are important to explore because they support antimicrobial stewardship and help maintain control of antimicrobials in the environment overall. Episode abbreviations and links:
About Dr. Marjon de Vos PhD: We investigate ecological and evolutionary processes in microbial communities, with a focus on infectious contexts. Our goal is to unravel the genotype–phenotype–fitness relationships within (evolving) communities and to identify the ecological factors that drive microbial evolution. To achieve this, we combine molecular biology techniques with phenotypic and growth measurements, as well as computational modeling. Our research places special emphasis on the urobiome and urinary tract infections in postmenopausal women, as well as on sepsis. By uncovering the fundamental ecological and evolutionary dynamics of microbial communities in infectious diseases, we aim to contribute to the development of strategies that alleviate infections and help curb the emergence and spread of antibiotic resistance. | |||
| Highlighted Posters from the 2025 ISAPP Annual Meeting | 28 Aug 2025 | 00:22:02 | |
In this second special episode about ISAPP’s annual meeting, held in Banff (Canada) in July 2025, Executive Director Marla Cunningham introduces the four highest-scoring posters from the poster session. Four speakers, all members of the ISAPP Students and Fellows association (SFA), join the podcast to describe the work they presented via poster at the meeting:
Episode abbreviations and links:
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| Highlighted Talks from the 2025 ISAPP Annual Meeting | 21 Aug 2025 | 00:28:16 | |
In this special episode, ISAPP’s Executive Director Marla Cunningham highlights ISAPP’s annual meeting, held in Banff, Canada in July 2025. Four speakers join the podcast to describe their talks from the meeting:
Episode abbreviations and links:
About our speakers: Carolina Tropini, University of British Columbia, Canada Dr. Carolina Tropini is an Assistant Professor at the University of British Columbia in the Department of Microbiology and Immunology and the School of Biomedical Engineering, and a Canada Tier 2 Research Chair in Quantitative Microbiota Biology for Health Applications. In 2020 she was nominated a Paul Allen Distinguished Investigator, and she was the first Canadian to be awarded the Johnson & Johnson Women in STEM2D Scholar, which was granted in the field of Engineering. She is the inaugural Alan Bernstein Canadian Institute for Advanced Research (CIFAR) Fellow in the Humans & the Microbiome Program and a Michael Smith Foundation for Health Research Scholar. In 2019, she was nominated as a CIFAR Azrieli Global Scholar. The Tropini lab is investigating how a disrupted physical environment due to altered nutrition or concurrent with intestinal diseases affects the microbiota and host at a multi-scale level. They are a cross-disciplinary group that incorporates techniques from microbiology, bioengineering and biophysics to create highly parallel assays and study how bacteria and microbial communities function, with the goal of translating the knowledge gained to improve human health. Dr. Tropini conducted her Ph.D. in Biophysics at Stanford University. Her studies in the laboratory of Dr. KC Huang combined computational and experimental techniques to investigate bacterial mechanics and morphogenesis. In 2014 she received the James S. McDonnell Foundation Postdoctoral Fellowship Award, and she joined the laboratory of Dr. Justin Sonnenburg at Stanford. During her post-doc, Dr. Tropini applied her background in biophysics to study the impact of physical perturbations on host-associated microbial communities living in the gut. André Marette, Université Laval, Canada Dr. André Marette is a Professor of Medicine and researcher at the Heart and Lung Institute Hospital Center (IUCPQ), and at the Institute of Nutrition and Functional Foods (INAF) at Laval University. He holds a Valbiotis Research Chair in plant bioactives and metabolic liver diseases and a Pfizer Research Fund in the pathogenesis of insulin resistance and cardiovascular complications. Dr. Marette is an international renowned expert on how nutrition and the microbiome modulate immunometabolic pathways involved in obesity and cardiometabolic diseases (CMD). He is investigating the metabolic impact of nutritional interventions and microbiome-based therapeutics (probiotics, prebiotics) using both clinical and pre-clinical studies, and uses various cellular models and molecular tools to discover novel disease biomarkers and mechanistic targets. Dr. Marette’s research work has been published in over 330 papers, reviews and book chapters and also authored two books. He has received several awards for his work including the prestigious Charles Best Award and Lectureship from the University of Toronto for his overall contribution to the advancement of scientific knowledge in the field of diabetes. Peijun Tian, Jiangnan University, P. R. China Peijun Tian is an Associate Professor and Master’s supervisor at the School of Food Science and Technology, Jiangnan University. He earned his Ph.D. in Food Science from Jiangnan University (January 2021) and was a visiting scholar at the APC Microbiome Institute, Ireland (September 2019–October 2020). He completed postdoctoral research at Jiangnan University, supported by the prestigious “National Postdoctoral Program for Innovative Talent” (top 1% in China). His research focuses on elucidating the interactions between gut microbiota and brain function, exploring the application of probiotics to mitigate stress, support neurodevelopment, and address neurodegenerative disorders. He has authored over 30 peer-reviewed articles, including three ESI Highly Cited Papers, with an H-index of 23 (Google Scholar, March 2025). In 2025, he was honored with the Glenn Gibson Early Career Researcher Award by the International Scientific Association for Probiotics and Prebiotics (ISAPP). Josiane Kenfack, University of Yaounde I, Cameroon Josiane Kenfack is a PhD student passionate about scientific research aimed at improving women’s health through the advancement of studies of the vaginal microbiome and probiotics. Josiane is co-coordinator of a citizen science project in Cameroon, the LEKE project. This project was inspired by the Isala project (https://isala.be/en/) which aims to better understand the female microbiome while raising awareness about vaginal health and breaking taboos. Through the LEKE project, Josiane and colleagues have conducted field activities to explore vaginal and menstrual health and promote good practices with women and men in rural and urban areas. In her ongoing research, she is investigating beneficial lactobacilli that could serve as biotherapeutics or probiotics development to combat conditions such as bacterial vaginosis, HIV, and sexually transmitted infections which are still prevalent in Africa. while she co-coordinates in Cameroon the IMVAHA project which aims to determine the impact of different menstrual products on the vaginal microbiome. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| Unraveling the functions of GLP-1 in the gut, with Dr. Thomas Greiner PhD | 17 Jul 2025 | 00:24:34 | |
This episode features Dr. Thomas Greiner PhD from the University of Gothenburg (Sweden), speaking about the various functions of GLP-1 in the gut, and the role of gut microbes in GLP-1 production, with ultimate effects on host health. He noted that GLP-1 is produced by enteroendocrine cells called L-cells, both in the small intestine and the colon. These cells respond to nutrients and microbially-produced short-chain fatty acids, but responses differ between the small intestine and colon, leading Dr. Greiner to investigate the different functions of GLP-1 at these two sites. Using germ-free mice and other models, Dr. Greiner has developed a hypothesis that the function of GLP-1 in the small intestine is to improve insulin secretion postprandially, whereas the functions of GLP-1 in the colon are to allow for increased energy intake (in a situation of energy deficiency), dampen inflammation, and protect local tissues. He and his colleagues are taking two different approaches in aiming to improve metabolic health in humans: finding inhibitors of bacterial enzymes to decrease production of a harmful molecule produced by bacteria; and a probiotic approach of administering butyrate-producing bacteria. With the latter approach, the sensitivity of the bacteria to oxygen is a problem to overcome, but their group has evolved a bacterial strain to tolerate some oxygen, with the idea of testing it as a probiotic. Episode abbreviations and links:
About Dr. Thomas Greiner PhD: Thomas Greiner is a medical scientist at the Wallenberg Laboratory, University of Gothenburg, with over 15 years of experience in functional genetics and metabolic research. His work focuses on the intricate interplay between gut microbiota, intestinal hormones such as GLP-1, and host metabolism. He has explored how microbial and hormonal signals influence energy balance, intestinal function, and the development of metabolic diseases. His research primarily uses molecular approaches in mouse models to investigate the role of microbial signals in metabolic disease and to uncover new functions of gut hormones in regulating intestinal physiology. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| Archive Highlight: Microbes that break down mucus and milk to benefit the host, with Dr. Clara Belzer PhD | 10 Jul 2025 | 00:28:40 | |
We discuss microbes, mucus, and milk with Dr. Clara Belzer PhD from Wageningen University in the Netherlands in this episode. Dr. Belzer, a molecular geneticist, specializes in studying the microorganisms that are equipped to break down the glycans in mucus and human milk within the host environment. Key topics from this episode:
Episode abbreviations and links:
About Dr. Clara Belzer PhD: Dr. Clara Belzer is Associate Professor Microbiology at the Laboratory of Microbiology of Wageningen University. The Belzer group is called ‘Microbes Mucus and Milk’ and the research is focused on the interaction of the gut microbiome with host mucus and milk. After obtaining her PhD at the Erasmus Medical Center Dr. Belzer did a postdoc at Harvard medical school. By now Dr. Belzer has years of experience on gut microbiome studies on anaerobes, including synthetic communities and different biotic concepts, with a special interest for the Akkermansia muciniphila. The group of Dr. Belzer works on several microbiome HMO and mucus related topics funded by national and international grants, some also in collaboration with medical centers and industry. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| Investigating the microbial mechanisms contributing to host metabolism, with Dr. Amir Zarrinpar, MD PhD | 03 Jul 2025 | 00:28:26 | |
This episode features Dr. Amir Zarrinpar, MD PhD, from UC San Diego (USA) speaking about his work on circadian biology and host metabolism, and what’s currently known about microbial mechanisms. Dr. Zarrinpar explains that in mouse models, restricting feeding to the nocturnal (awake) period is important for their metabolic and overall health. When mice eat during the nocturnal period, the microbiome is very dynamic and essential for maintaining normal circadian rhythm. On a high-fat diet, they change their feeding timing and sleeping behavior simultaneously, and the microbiome fluctuations are disrupted. However, when mice experience time-restricted feeding they are protected from the deleterious consequences of the high-fat diet. The hypothesis is that the time-restricted feeding restores the normal circadian fluctuations of the microbiome. Even though the composition doesn’t change much, the microbes may be changing what they’re doing. Dr. Zarrinpar has used metatranscriptomics to find out what the microbes are actually doing (what genes they’re using), and saw patterns that correlated with time-restricted feeding, indicating that the microbiome may play a key role in the beneficial metabolic effects of time-restricted feeding. Overall, the host may be trying to interpret what’s happening in the environment through microbial signals. The key question to answer going forward is why certain microbe-derived signals prompt the host to alter its metabolic response. Episode abbreviations and links:
About Dr. Amir Zarrinpar, MD PhD: Dr. Amir Zarrinpar is an Associate Professor in the Division of Gastroenterology at UC San Diego. Dr. Zarrinpar is a renowned expert in the field of microbiome research and its applications to human health and disease. His work focuses on understanding the complex relationships between the gut microbiome, circadian rhythms, and host metabolism, with the goal of developing novel therapeutic strategies for diseases such as obesity, diabetes, and liver disease. Dr. Zarrinpar has published numerous papers in top-tier journals and has received several awards for his research, including the Litwin IBD Pioneer Award and the American Gastroenterological Association’s Microbiome Junior Investigator Research Award. He is also a dedicated mentor and educator, having supervised numerous students, fellows, and junior faculty members in his laboratory. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| Interactions between immunity, gut microbiota, and metabolism, with Prof. Dirk Haller PhD | 28 Jun 2025 | 00:27:53 | |
This episode features Prof. Dirk Haller from Technical University of Munich (Germany) speaking about his work in the field of nutritional immunology, trying to unravel how immunity and gut microbiota interact with metabolism, ultimately impacting the emergence of chronic diseases. He focuses on how microbe-host interactions in the gut impact inflammatory or tumorigenic responses – essentially, the microbiota adapts and this drives disease progression. He sees the gut microbiota as a new dimension in nutrition science, with nutrients shown to trigger metabolic changes and impact the microbial environment in the gut. Interestingly, circadian rhythms (which also impact metabolism) seem to establish within the first year of life; and when a relevant microbial community is removed from the host for a week or two, it still shows diurnal oscillations. Lots of uncertainty still exists within the field, however. Prof. Haller recommends that gut microbiome studies report the timing of fecal sample collection, as it can be a major confounder. The metabolic output of microorganisms doesn’t correlate directly with the metabolic health of the host, so much more research needs to be done. Episode abbreviations and links:
About Prof. Dirk Haller PhD: Prof. Dirk pioneered the field of nutrition and microbiome research, and over the past two decades, he developed highly innovative and truly interdisciplinary research at the borders of different scientific fields. He finished two study programs emphasizing human nutrition and microbiology, before becoming engaged with the fascinating world of commensal microbes in the digestive tract and their impact on human health and diseases. He holds the Chair of Nutrition and Immunology at the Technical University of Munich and chronic intestinal inflammation became his prime research paradigm. In more than 250 publications, he developed ground-breaking and novel concepts to the question of how the non-infectious community of commensal bacteria contributes to the pathogenesis of chronic pathologies in the digestive tract. He developed Priority and Collaborative Research Programs thereby building microbiome research in Germany. Receiving the Main Award of the German Society of Medical Microbiology in 2015, the distinguished Research Award of the United European Gastroenterology Association in 2021, and the recognition as Highly Cited Scientist in 2024 highlights his global scientific reputation across disciplines. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| Examining fermented foods for potential cardiometabolic health benefits, with Prof. Ben Willing PhD | 21 Jun 2025 | 00:23:27 | |
This episode features Prof. Ben Willing PhD from the University of Alberta, Canada, speaking about his work investigating fermented foods such as kefir for potential cardiometabolic health benefits. The microorganisms associated with fermented foods are not standardized – for example, traditional kefirs have some microorganisms in common, but other microorganisms that are present sporadically. Moreover, kefir at the supermarket is created by taking microbial isolates (not necessarily associated with traditional kefir) and introducing them into the product. Several yeast species are present in traditional kefir but not in supermarket kefir. Prof. Willing studied the health benefits associated with traditional fermented kefir. His group found that specific kefir grains that could lower cholesterol in a mouse model and lower immune markers associated with cardiovascular disease; however, not all traditional kefirs had the same effect and supermarket kefirs were not effective. They isolated a set of 9 microorganisms to make the kefir in the lab, which were sufficient to replicate the effect. The ultimate goal is to produce a product that could be used at a commercial scale and is effective for human health. In initial human studies, the product showed a positive effect. Interestingly, a Canadian public survey about fermented foods found that consumers often expect a health benefit from fermented foods; this is an important area for future scientific and regulatory progress. Episode abbreviations and links:
About Prof. Ben Willing PhD: Prof. Willing is a Professor of Gut Microbiology and former Canada Research Chair (Tier 2) in Microbiology of Nutrigenomics in the Department of Agricultural, Food and Nutritional Science at the University of Alberta. He completed his PhD at the University of Saskatchewan studying the role of the microbiota in intestinal development in gnotobiotic pigs. His postdoctoral training was at the Swedish Agricultural University in Uppsala Sweden with Prof. Janet Jansson where he studied the relationship between the microbiome and inflammatory bowel diseases in a twin cohort, and at the University of British Columbia with Prof. Brett Finlay where he studied the impact of antibiotics and faecal transplantation on infection resistance and asthma. His research group is working to understand both fundamental and applied questions in gut microbiology, with a particular focus on how it interacts with diet and antibiotic exposures. Fundamental research includes identifying mechanisms through which specific core members of the microbiome regulate host physiology using gnotobiotic piglet and mouse models to understand their impact on infection resistance, metabolic disease and multiple sclerosis. Applied questions include developing and testing the impact of fermented foods on human health using clinical trials. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| Diet and gut microbiome contributions to host energy balance, with Dr. Karen Corbin PhD RD | 12 Jun 2025 | 00:33:20 | |
This episode features Dr. Karen Corbin PhD RD from AdventHealth Translational Research Institute (USA), speaking about how the triad of diet, gut microbiome, and host characteristics contribute to energy balance as well as metabolic diseases. From the perspective of host physiology, she explores how to use diet to remodel the gut microbiome to impact energy balance in healthy individuals and those with obesity. Energy balance relates to many different diseases: metabolic diseases and even brain-related conditions. Her center is equipped to measure energy metabolism very precisely and deeply, controlling participants’ energy intake and measuring the resulting oxygen consumption and carbon dioxide production. Diets that feed the gut microbiome lead to more fecal energy loss and higher microbial biomass, indicating that some of the dietary energy is not absorbed by the host, but rather is used for biomass growth. Diet is a must-have in gut microbiome studies because researchers need to know what substrates the microbes are seeing from the host diet. Overall, the field needs to balance highly controlled studies with real-world studies and interpret the results together. Metabolite analysis is a quickly evolving area; some metabolites are associated with leanness or obesity. Other metabolites are promising for revealing a participant’s dietary intake (as Gibbons lab work has shown). Dr. Corbin is exploring the concept that possibly some people – because of genetics, microbiome, or other factors – reabsorb more of the energy substrates produced in the colon. An oversupply of energy to the host is detrimental for metabolic-related diseases, so in the future perhaps a precision intervention could be developed that prevents the gut microbiome from allowing the host to absorb an excess amount of energy. Episode abbreviations and links:
About Dr. Karen Corbin PhD RD: Karen Corbin, PhD, RD, is an Associate Investigator at the AdventHealth Translational Research Institute and the Founder and Chief Geek of Geeks That Speak. Dr. Corbin’s scientific career is focused on human nutrition and metabolism. She explores the mechanisms, including the gut microbiome, that drive individual susceptibility to metabolic diseases such as and obesity, diabetes and liver disease. Her overall goal is to advance clinically relevant research that is poised to transform patient care. Dr. Corbin is also an expert in scientific storytelling. She founded Geeks That Speak to help scientists and other “geeks” to deliver complex scientific information in a way that is impactful, relevant and inspires action. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| Progress in understanding the gut microbiome’s role in health and disease states, with Prof. Emad El-Omar MD FRCP | 05 Jun 2025 | 00:22:08 | |
This episode features Prof. Emad El-Omar MD FRCP from the University of New South Wales in Sydney, Australia, speaking about a recent paper exploring the healthy microbiome concept, as well as the latest research on how the gut microbiome contributes to the pathophysiology of several diseases. Prof. El-Omar talked about research on H. pylori-induced disease in the stomach; it’s known that these bacteria decrease acid secretion, which shifts the gastric microbiology in a way that drives progression to cancer. Prof. El-Omar recently co-authored a review paper in Gut that addressed the definition of a healthy gut microbiome. Although a definition has not yet been established, progress is being made by studying healthy people such as centenarians around the world. The best approach may be to define a core microbiome signature that’s present across healthy phenotypes. The core is likely defined by the gut microbiome’s function, so diverse compositions may be able to support health. The paper authors emphasize that pursuing knowledge about what makes a healthy microbiome is a worthwhile pursuit, and they outline what research is necessary to make continued progress in this area. Validation and reproducibility are critical for moving toward clinical applications. Episode abbreviations and links:
About Prof. Emad El-Omar MD FRCP: Professor El-Omar graduated in Medicine from Glasgow University, Scotland, and trained as a gastroenterologist. He worked as a Visiting Scholar/Scientist at Vanderbilt University, TN, and National Cancer Institute, MD, USA, and was Professor of Gastroenterology at Aberdeen University, Scotland, for 16 years before taking up the Chair of Medicine at St George & Sutherland Clinical School, University of New South Wales, Sydney, Australia. He is the Editor in Chief of the journal Gut. His research interests include all aspects of the microbiome, inflammation driven GI cancer and IBD. He is the Director of the Microbiome Research Centre at UNSW/St George Hospital, Sydney. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| The HACK index for measuring a health-associated gut microbiome, with Dr. Tarini Ghosh PhD | 30 May 2025 | 00:29:04 | |
This episode features computational microbiologist Dr. Tarini Ghosh PhD from Indraprastha Institute of Information Technology (Delhi, India) speaking about his recently published paper that proposes a novel Health-Associated Core Keystone (HACK) index for measuring a healthy microbiome. To create the index, the group used a huge volume of sequence data – over 201 terabytes – from more than 45,000 individuals with and without disease across different geographies. The ultimate aim is to create a universal measure for a health-associated microbiome. The HACK index is based on taxa in the gut microbiome, and consists of 3 components: (1) prevalence and connectedness in the gut microbiome of healthy individuals, (2) longitudinal stability, and (3) association with disease. Keystone taxa were generally more prevalent / abundant in the gut microbiome but not always. The group is now working to connect the identified taxa to specific functions. In the future, this index may be used as a diagnostic tool, possibly to predict a positive response in clinical trials. Episode abbreviations and links:
About Dr. Tarini Ghosh PhD: Dr. Tarini Shankar Ghosh leads the Microbiome Informatics group at the Department of Computational Biology at the Indraprastha Institute of Information Technology – Delhi, India. His research focuses on mining global microbiome datasets using advanced statistical methods, machine learning, and deep learning to develop predictive models and indexes that can facilitate formulation of novel microbiome-derived clinical end-points along with the development of generic and population-specific microbiome-derived diagnostics/therapeutics. His research includes identifying the global and cohort-specific markers of microbiome-resilience and disease, investigating the microbiome taxa associated with response to different therapies and cross-body-site microbiome associations. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| Regulatory science and the development of microbiome biomarkers, with Dr. Céline Druart PhD | 22 May 2025 | 00:23:17 | |
This episode features Dr. Céline Druart PhD of Pharmabiotic Research Institute (PRI) speaking about the role of regulatory science in the development of microbiome biomarkers. First, PRI’s Communication and Membership Manager Camille Bello briefly describes the work of the PRI in supporting the development of therapeutic and diagnostic products derived from microbiome science. Regulation is important to protect consumers and reward innovation, and the development of biomarkers that predict response to treatment, for example, can help move toward personalized medicine. Dr. Druart notes many potential microbiome-based biomarkers have emerged but none have been successfully validated to date. Regulation always follows innovation, and regulatory science is important because it helps regulatory frameworks evolve. A recent Delphi consensus paper co-authored by Dr. Druart acknowledges that biomarker development is a complex process and that a particular challenge is the lack of validation of analytical methods for measuring the microbiome. However, it’s important to remember that techniques can continue to improve even after they’ve been validated. Dr. Druart argues that biomarker validation needs public-private collaborations to design and execute the large clinical studies that are necessary. Episode abbreviations and links:
About Dr. Céline Druart PhD: Céline Druart obtained her PhD in Biomedical and Pharmaceutical Sciences from UCLouvain (Belgium) in 2014. Following a 3-year project in Patrice Cani’s research group focused on developing the potential beneficial effects of a human gut commensal Akkermansia muciniphila, she worked for 3 years at A-Mansia Biotech (now known as The Akkermansia Company), responsible for clinical programs, regulatory affairs and IP dossiers, as the Scientific and Business Project Manager. Céline joined the PRI in July 2021 as Microbiome Project Manager, managing the Regulatory Science activities of the Association, coordinating Task Group work, and supporting PRI Industry Members in their development planning. She became the PRI’s Executive Director in January 2024. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| Identifying features of a healthy microbiome, with Raphaela Joos | 15 May 2025 | 00:27:18 | |
This episode features Raphaela Joos from University College Cork in Ireland, speaking about efforts by the Human Microbiome Action Consortium to create an expert-led consensus around the concept of a healthy human microbiome. Ms. Joos, a PhD student who was first author of the resulting paper, notes that a healthy human microbiome can be defined at many different levels. Some parameters such as diversity and resilience are good for a microbial community, and other parameters such as antimicrobial resistance are good for the microbial community but not necessarily good for the host. Another challenge with the definition was how to define health. The group decided that the definition of healthy microbiome needed to be more inclusive than just the microbiome of a healthy person with no disease diagnoses. At present, causality is not clear so we don’t know whether disease-associated microbiomes are adaptive or are driving the disease. The main consensus that emerged from this expert discussion was that more data are needed, tracking large cohorts of people over time in many geographical areas. Only in this way will it be possible to overcome individual variability and truly identify the robust features of a healthy microbiome. Different microbiome compositions can have similar functional capacities, so possibly a functional signature will emerge. Episode abbreviations and links:
About Raphaela Joos: Born and bred in Germany, I obtained my BSc in Psychology with a focus on biological neuropsychology, nutrition and statistics at Leiden University and the University of Melbourne. Fascinated by nutritional science and its impact on mental health, I then pursued a MSc on the topic of Microbiome in Health and Disease at King’s College London, delving into microbiology, bioinformatics and microbiome science. After the masters I moved to Cork for a research assistant position investigating the structure and infection mechanisms of bacteriophages involved in cheese fermentation using the protein-folding software AlphaFold. Before starting my PhD, I worked as a project manager under Prof Paul Ross and Prof Aonghus Lavelle on the Human Microbiome Project, organising a workshop featuring international leaders in microbiome research to establish a roadmap to define a healthy microbiome. My PhD now focuses on investigating the role of the infant microbiome in development, applying statistical modelling strategies to integrate functional microbiome data with clinical data. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| Advancing gut microbiome testing for use in clinical practice, with Dr. Gianluca Ianiro MD PhD | 08 May 2025 | 00:24:09 | |
This episode features Dr. Gianluca Ianiro MD PhD, a gastroenterologist from the Fondazione A. Gemelli IRCCS and Università Cattolica del Sacro Cuore in Rome (Italy), speaking about how to advance gut microbiome testing for use in medicine. His interest in the gut microbiome began with the clinical observation that fecal microbiota transplantation (FMT) was remarkably successful at curing recurrent C. difficile infection – and from there, he began a program of research on FMT. Current gut microbiome tests are widely variable and don’t provide any clinically relevant information, but some people do them out of curiosity. Over the years it’s become increasingly clear that gut microbiome testing must be standardized to move toward clinical utility. Dr. Ianiro co-authored a recent consensus paper on the challenges of gut microbiome testing and how to move toward standardization. He describes several initiatives that aim to standardize and validate gut microbiome testing, from sample collection to analysis. Dr. Ianiro says promising data exist for gut microbiome testing to predict colorectal cancer, to predict the response to some cancer treatments, and to diagnose inflammatory bowel disease. The field is moving toward some important factors that define a microbiome as “healthy”, but these need to be associated with a clear health outcome if they’re eventually to be used in clinical practice. Episode abbreviations and links:
About Dr. Gianluca Ianiro MD PhD: Gianluca Ianiro is a gastroenterologist at the Digestive Disease Center of the Fondazione A. Gemelli IRCCS and adjunct professor in gastroenterology at the Università Cattolica del Sacro Cuore in Rome, Italy. He has since gone on to establish himself as a key clinical and translational investigator focusing mainly in the field of intestinal microbiota, and has received several research grants in support of his innovative research. His current research is focused mainly on disentangling the rules of donor microbiome engraftment, on investigating microbiome diagnostics and therapeutics in noncommunicable disorders (including cancer), and on bringing microbiome into clinical practice. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| Archive Highlight: Human milk oligosaccharides in the infant gut, with Dr. Simone Renwick PhD | 01 May 2025 | 00:20:57 | |
In this episode, the ISAPP hosts discuss human milk and the infant gut with Dr. Simone Renwick PhD from Mother-Milk-Infant Center of Research Excellence (MOMI CORE) at UC San Diego, USA. Dr. Renwick talks about her work investigating how communities of microbes versus individual microbes in the infant gut metabolize human milk oligosaccharide (HMO) structures, and what we know about the origin and functions of the microbes contained in human milk. Key topics from this episode:
Episode links:
About Dr. Simone Renwick PhD: Dr. Simone Renwick is the Milk & Microbes postdoctoral fellow at the Mother-Milk-Infant Center of Research Excellence (MOMI CORE) at the University of California, San Diego, USA. Her research focuses on understanding the role of human milk components, such as the human milk oligosaccharides (HMOs) and milk microbiota, in fostering the developing infant gut microbiota. She is also interested in the potential therapeutic applications of milk components in diseases that affect adults. Currently, Simone is supervised by Drs. Lars Bode, Rob Knight, Pieter Dorrestein, and Jack Gilbert. Prior to her postdoc, Simone completed her PhD in Molecular and Cellular Biology (MCB) at the University of Guelph, Canada, under the supervision of Dr. Emma Allen-Vercoe. She was the recipient of the Students and Fellows Association poster prize at the ISAPP 2023 meeting in Sitges, Spain. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| How a non-industrialized diet affects gut microbes and health, with Dr. Anissa Armet PhD RD | 26 Apr 2025 | 00:29:19 | |
This episode features Dr. Anissa Armet PhD RD from the University of Alberta in Canada, speaking about the impact of diet on both the gut microbiota and overall health. Dr. Armet, a registered dietitian and researcher, says the Western diet along with the associated gut microbiome changes have played a role (amongst other things) in the rise of autoimmune diseases in industrialized societies. Dr. Armet describes a recent dietary study she and her collaborators published, for which they created a very high fiber diet called the Non-Industrialized Microbiome restore (NiMe, pronounced “nee mee”) diet. They created recipes and meal plans based on what some non-industrialized populations in the world typically consume, which included 45 grams of dietary fiber per day, and only small portions of animal proteins and dairy products. The participants in this controlled feeding trial saw substantial cardiometabolic benefits as well as certain changes in the gut microbiota after three weeks on the diet. Interestingly, the diet initially reduced the diversity of participants’ gut microbiota, likely because of increased pH in the gut, but diversity rebounded toward the end of the trial. The researchers also introduced a strain of L. reuteri isolated from the gut microbiota of people in a non-industrialized society, to observe whether it would engraft since the diet was known to contain growth substrates for the bacteria. Although the strain did not engraft in the gut microbiota (except in one participant), the health benefits of the diet overall were still observed. The researchers concluded that the NiMe diet can be used to target the gut microbiome and change community characteristics that are relevant for health. Episode abbreviations and links:
About Dr. Anissa Armet PhD RD: Dr. Anissa Armet is a Registered Dietitian and postdoctoral researcher at the University of Alberta. Anissa completed her PhD in Nutrition and Metabolism in March 2024, then transitioned into her postdoc to research the effects of microbiome-targeted dietary interventions in inflammatory bowel diseases. She uses machine learning to determine if the gut microbiome predicts clinical responses in the context of precision nutrition. Anissa has authored several peer-reviewed publications, including a review on healthy eating in light of the gut microbiome and a dietary intervention trial on microbiome restoration. Being equally passionate about knowledge translation, Anissa co-authored an award-winning, open-access, high-protein cookbook designed to support muscle health, is currently developing a plant-based version, and recently co-authored an open-access ebook, The NiMe Diet: Scientific Principles and Recipes. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| Interactions of polyphenols in the gut, with Prof. Yves Desjardins PhD | 17 Apr 2025 | 00:30:31 | |
This episode features Prof. Yves Desjardins PhD from Laval University in Canada. Prof. Desjardins, an agrologist by training, explains that polyphenols are metabolites synthesized by plants and present in the plant foods we consume. When humans consume polyphenols, we absorb a small fraction (around 5%) of them in the upper gastrointestinal tract, but most of them reach the colon and interact in various ways with the gut microbiota. They have two main effects in the gut, which appear somewhat contradictory: antibacterial effects and a prebiotic-like effect. In the latter case, polyphenols interact with the host epithelium to induce mucin production, creating a niche for certain bacteria to grow. Typical bacteria that increase under these circumstances are bifidobacteria and Akkermansia muciniphila. In these ways, polyphenols have an impact on certain microorganisms and on the microbiome as a whole. In the future, supplements with polyphenols and fiber may be designed to help manipulate the microbiome in a certain way. Currently there are many health benefits associated with polyphenols. The primary benefit is for cardiometabolic health, and some studies also show benefits for cognition. Episode abbreviations and links:
About Prof. Yves Desjardins PhD: Yves Desjardins is a full professor at the Institute of Nutrition and Functional Foods, Laval University, Québec, Canada. He holds the NSERC/Symrise Partnership Chair on the prebiotic effects of polyphenols (PhenoBio+). Trained in plant physiology, his research focuses on the phytochemistry and functionality of plant bioactives. He has led numerous preclinical and clinical studies on type-2 diabetes, cognitive decline, inflammation, and infections. His current work explores the impact of tannins on gut microbiota, mucosal immunity, and gut barrier function. He has collaborated with the food industry to validate the health benefits of horticultural products (e.g., Urophenol, Glucophenol, Neurophenol). Recognized for his innovative research on fruit polyphenols, he chaired the first International Symposium on Health Effects of Fruits and Vegetables (FAVHEALTH 2005), the OECD Symposium in Lisbon (2010), and organized the 2017 International Congress on Polyphenols and Health in Québec City. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| The interplay between gut microbiota, diet, and circadian rhythms, with Dr. Vanessa Leone PhD | 03 Apr 2025 | 00:32:14 | |
This episode features Dr. Vanessa Leone PhD from the University of Wisconsin – Madison on how gut microbes and eating patterns impact the host circadian system and overall health. In mouse models, Dr. Leone has found that in a 24-hour period, minor changes occur in the composition of the gut microbiota, while more important changes occur in gut microbiota function (that is, metabolite production). However, these changes depend on the type of diet and the timing of meal consumption. Metabolic health is also affected by this interplay. In humans, obesity is correlated with loss of microbiota rhythmicity, although causality remains unclear. One study by Dirk Haller found that a loss of rhythmicity helped predict which people with prediabetes would progress to diabetes. Constantly shifting timezones (or shifting between day and night shifts) appears to be more detrimental to metabolic health than maintaining a constant schedule, and research is ongoing about what might mitigate these effects. In this field of research it’s important to consider people’s chronotype: their tendency to rise early versus stay up late. In the future, Dr. Leone hopes to untangle more about how different factors affect metabolic health: diet, gut microbiota, and the circadian system. Episode abbreviations and links:
About Dr. Vanessa Leone PhD: Vanessa A. Leone, Ph.D. is an Assistant Professor in the Department of Animal & Dairy Sciences at the University of Wisconsin-Madison, where she also obtained a Ph.D. She performed postdoctoral studies and was an Instructor of Medicine at the University of Chicago in the Section of Gastroenterology, Hepatology, & Nutrition where she examined how the gut microbiome impacts complex metabolic diseases. Dr. Leone currently studies how day vs. night oscillatory patterns of gut microbes influence the body’s internal clock and metabolism. She hopes to mechanistically define what constitutes a microbial oscillator versus a non-oscillator, examine how host factors impact the broader diurnal structure and functional outputs of the gut microbiome, and to determine how microbial oscillations impact host metabolism. These findings will likely pave the way to identify how timed delivery of pre-, pro-, or postbiotics can be leveraged to promote a balanced gut microbiota and improve host health. Sign up for our monthly newsletter Follow us on LinkedIn, Bluesky, X, Facebook, Instagram, Threads | |||
| An overview of precision fermentation, with Prof. William Chen PhD | 13 Mar 2025 | 00:24:36 | |
This episode features Prof. William Chen from Nanyang Technological University in Singapore, speaking with the ISAPP hosts about precision fermentation. In Singapore, enhancing national food security is of interest and one of the technologies used to achieve this is precision fermentation. Prof. Chen describes the differences between traditional fermentation, biomass fermentation, and precision fermentation. In precision fermentation, food scientists use genetically modified microorganisms to produce a food ingredient of interest. In some cases the product is secreted out of the cell, and in other cases it must be extracted from the cell. The approach has great potential to bypass the need for a large amount of land to produce food, and may reduce costs associated with food production. As this approach continues to develop, education and transparency with consumers is key. Regulatory frameworks and approval processes differ from country to country, and this is an area that will continue to evolve in the years ahead as more food ingredients or other useful products are generated. Episode abbreviations and links: About Prof. William Chen PhD: William Chen is the Michael Fam Endowed Professor and Director of Food Science & Technology Programme at Nanyang Technological University Singapore. He is concurrently Director of Singapore Future Ready Food Safety Hub (FRESH). He is also Director of Singapore Agri-food Innovation Lab. Professor Chen is active in securing and leading large competitive research grants from major government agencies as well as leading international food companies. His food technology innovations have been extensively attracting global attention. His views on food tech innovations, food safety and food security have been regularly covered by major local and international media outlets. He is also advisor/consultant to overseas universities, Singapore government agencies, food industry, and international organizations (ADB, FAO, WHO among others). | |||
| Precision fermentation for animal-free milk, with Dr. Abigail Thiel PhD | 21 Feb 2025 | 00:28:42 | |
This episode features Dr. Abigail (Abbey) Thiel PhD, who works remotely (from the US) with Wageningen University to manage a project focused on developing animal-free milk proteins using precision fermentation. Dr. Thiel explains that the motivation for the project is to find alternatives to animal-produced foods using microorganisms to produce key components of dairy products. Her project focuses on producing the protein casein, which is found in milk (and contributes to its structure and stability), to eventually produce a milk substitute or a protein powder that could be used as a food ingredient. A specific yeast is used to produce the casein: the scientists insert directions for making the protein into the yeast, then put it in a bioreactor to produce the protein. After that, they figure out how to purify the protein so it can be used in various applications. The final step is upscaling the process to produce abundant and cost-effective casein. The group has also started initial digestion studies to see how the purified casein is digested. Meanwhile, Dr. Thiel is passionate about food science communication and has a YouTube channel called Abbey the Food Scientist, where she strives to build awareness of food science as a career and also to address myths about food science. Episode abbreviations and links:
About Dr. Abigail Thiel PhD: Abigail (Abbey) Thiel is a food scientist, educator, and project manager of research focused on producing milk proteins using yeast. She earned her PhD in Food Science from the University of Wisconsin-Madison and later worked as a postdoctoral researcher at Wageningen University & Research in the Netherlands. Abbey is passionate about making the science behind food accessible to all. She runs a successful YouTube channel with over 1.4 million views, breaking down food science concepts for everyday audiences, and created an online course, Food Science for Beginners. In addition, she develops high school curriculum and educational resources to help students explore food science as a career path. | |||
| Archive Highlight: An evolutionary perspective on fermented foods, with Assoc. Prof. Katie Amato | 20 Feb 2025 | 00:26:15 | |
Continuing in the series on the latest fermented food science, we are highlighting Episode 9 from our archives. In this episode, the ISAPP hosts talk about fermented foods and non-human primates with Katie Amato of Northwestern University, USA. Amato describes what she has learned from studying the gut microbiota of non-human primates and how it relates to our understanding of human and gut microbial co-evolution over time. She also talks about non-human primate behaviors around fermented foods and what they might tell us about the need for human fermented food consumption. Key topics from this episode:
Episode abbreviations and links: Dissertation study: The Gut Microbiota Appears to Compensate for Seasonal Diet Variation in the Wild Black Howler Monkey (Alouatta pigra) Study: Fermented food consumption in wild nonhuman primates and its ecological drivers Mentors mentioned: Kathy Cottingham, Matt Ayres, David Peart, John Gilbert, Mark McPeek, Craig Layne, Rob McClung. Additional resources: Research on the microbiome and health benefits of fermented foods – a 40 year perspective. ISAPP blog About Assoc. Prof. Katie Amato: Dr. Amato is a biological anthropologist at Northwestern University studying the influence of gut microbes on host ecology and evolution. Her research examines how changes in the gut microbiota impact host nutrition, energetics, and health. She uses non-human primates as models for studying host-gut microbe interactions in selective environments and for providing comparative insight into the evolution of the human gut microbiota. Her main foci are understanding how the gut microbiome may buffer hosts during periods of nutritional stress and how the gut microbiome programs normal inter-specific differences in host metabolism. Dr. Amato is the President of the Midwest Primate Interest Group, an Associate Editor at Microbiome, an Editorial Board member at Folia Primatologica, and a Fellow for the Canadian Institute of Advanced Research’s ‘Humans and the Microbiome’ Program. | |||
| Fermented foods and their health benefits, with Dr. Paul Cotter PhD | 14 Feb 2025 | 00:26:00 | |
This episode features Dr. Paul Cotter PhD of TEAGASC in Ireland, talking about the creation of fermented foods and how they can lead to health benefits. A huge array of foods can be fermented, and historically fermentation was used to extend the shelf life of a food that people had an abundance of. Dr. Cotter’s work in the field originally started with a bacteria-killing bacteriocin that had been isolated from kefir, and later moved toward the microbes in fermented foods. Currently he’s interested in comparing the artisanal approach to fermented foods, which leads to somewhat unpredictable results in the final products, with the industrial approach, which leads to more consistent results. In different artisanal fermented foods, which strains are common and which are unique? Potentially some of the strains can be used to confer a health benefit, and even a benefit that’s personalized to an individual. Dr. Cotter sees the role of fermented foods as possibly targeting pre-disease rather than disease if their ability to confer health benefits can be unravelled further. Episode abbreviations and links:
Additional resources: ISAPP infographic: Fermented foods About Dr. Paul Cotter PhD: Prof Paul Cotter is the Head of Food Biosciences at Teagasc (the Irish Agriculture and Food Development Authority), is a Principal Investigator with the large Irish Research Centres, APC Microbiome Ireland, VistaMilk and Food for Health Ireland and head of microbiology/co-founder of SeqBiome, a microbiome sequencing and bioinformatics service provider. He is a molecular microbiologist, with a particular focus on the microbiology of foods (especially fermented foods), the food systems and of humans, as well as probiotics and postbiotics. Prof Cotter is the author of >400 peer-reviewed, was included in the Clarivate list of highly cited researchers for 2018-2024, received an honorary doctorate from the University of Antwerp in 2024 and is the Field Chief Editor of Frontiers in Microbiology. | |||
| How fermented foods can support health and sustainability, with Prof. Christophe Courtin PhD | 06 Feb 2025 | 00:25:10 | |
In this episode, Prof. Christophe Courtin PhD from KU Leuven in Belgium discusses the potential of fermented foods to provide health benefits and create more sustainable food systems. His work focuses in particular on fermenting cereal grains as a way to create products with better properties or enhanced health impact. Fermentation is a form of food processing that can introduce benefits beyond the raw materials used. Prof. Courtin leads HealthFerm, a European project with the aim of generating research on fermentation that supports a transition to more plant-based products in the diet, using wheat, oats, fava bean, and yellow pea. Fermentation can be scaled up both in industrialized countries and in developing countries. More intervention studies are needed to find out the health-promoting components of fermented foods and their mechanisms – although scientists know a fair amount about yogurt and other fermented dairy products, evidence is needed for other types of fermented foods. This episode is part of our series on the latest fermented food science. Episode abbreviations and links:
Additional resources: ISAPP blog post: Food of the future: Fermented and sustainable About Prof. Christophe Courtin PhD: Prof. Christophe Courtin is a full professor at the Laboratory of Food Chemistry and Biochemistry at KU Leuven, Belgium. His research focuses on cereal constituents, the enzymes that degrade them and microorganisms in cereal processing. The emphasis is on a basic understanding of the structure and properties of these constituents as well as on their technological and health functionality in cereal-based processes and products. Expertise and an extensive network in this area have been built up through over 40 supervised PhDs, projects and national and international collaborations. He coordinates HealthFerm, a 23 partner Horizon Europe project. He is author of 350 peer-reviewed papers (WoS h-index: 69) and inventor on 12 patent families. Recent awards are the Harald Perten Prize (ICC, 2021) and the Belfort Lecture Award (Whistler Centre for Carbohydrate Research, Purdue University, 2023). | |||
| 2024 highlights in biotic science, with ISAPP’s current and past Presidents | 31 Jan 2025 | 00:25:37 | |
In this episode, ISAPP’s current President Prof. Maria Marco PhD and past President Prof. Dan Merenstein join the podcast hosts for a conversation about highlights in biotic science from the past year. Prof. Marco points out a paper published in Nature Microbiology, the result of an ISAPP discussion group exploring whether diet may be a confounder of biotic effects in clinical studies. The group concluded that scientists should work with dietitians to include data on participants’ habitual diet in future studies on biotics – particularly with on prebiotics. These efforts will help scientists establish causality and understand the basis of individual responses to a biotic intervention. Prof. Merenstein highlighted conversations in 2024 around the role of probiotics in the neonatal intensive care unit (NICU), including ISAPP’s panel on this topic at the annual meeting in Cork, Ireland. Although US regulators have recently warned against the use of probiotics for preterm infants in the NICU setting, the data overwhelmingly points to benefits and this may eventually drive regulatory change. Prof. Marco added that a take-away from ISAPP’s panel was that parents of preterm infants should be included in the decision-making around whether to use probiotics. The guests talked about Prof. Merenstein’s recent appointment to the National Academy of Medicine and his rigorous approach to primary care research. Further highlights in the science this year were ISAPP’s papers exploring evidence for probiotics restoring an antibiotic-disrupted microbiota, and evidence for the benefits of probiotics in healthy individuals – both of which found a lack of conclusive evidence to answer these questions. Many gaps exist in the knowledge around biotics, gut microbiota, and health – for example, another paper this year found that the abundance of microorganisms in a fecal sample is a confounder of microbiome-disease associations. And finally, beyond the scientific advancements, conveying the scientific concepts to the general public requires careful consideration and dedicated effort. Episode abbreviations and links:
About Prof. Maria Marco PhD Dr. Maria Marco, PhD, is a Professor in the Department of Food Science and Technology at the University of California, Davis. She earned her bachelor’s degree in microbiology at The Pennsylvania State University and her PhD in microbiology at the University of California, Berkeley. As a postdoc at NIZO food research in The Netherlands, she developed a love for lactic acid bacteria and the importance of these microorganisms in our foods and the digestive tract. Her postdoctoral studies led to the discovery that probiotics are metabolically active in the intestine and responsive to dietary intake. Dr. Marco started her lactic acid bacteria and gut health laboratory at UC Davis in 2008 and has built an internationally-recognized, NIH, USDA, and NSF funded research program on probiotics, fermented foods, and dietary modulation of the gut microbiome. Dr. Marco also consults with and has received funding from international foundations and companies to investigate how certain microbes in foods or supplements may benefit health. She is active with science communication activities such as the EATLAC project and is the instructor for two food microbiology courses. Dr. Marco received the American Society for Microbiology Distinguished Lecturer award in 2012. Recently, she founded the ongoing Gordon Research Conference series on Lactic Acid Bacteria. Dr. Marco attended her first ISAPP meeting as a postdoc and participated as an invited expert before joining the ISAPP Board of Directors in 2019. About Prof. Dan Merenstein Dr. Daniel Merenstein, MD, is a Professor with tenure of Family Medicine at Georgetown University, where he also directs Family Medicine research. Dr. Merenstein has a secondary appointment in the undergraduate Department of Human Science, in the School of Health. Dr. Merenstein teaches two undergraduate classes, a research capstone and a seminar class on evaluating evidence based medical decisions. He has been funded by PCORI, NIH, USDA, foundations and industry. The primary goal of Dr. Merenstein’s research is to provide answers to common clinical questions that lack evidence and improve patient care. Dr. Merenstein is a clinical trialist who has recruited over 2,000 participants for 10 probiotic trials since 2006. He is an expert on probiotics, on antibiotic stewardship in outpatient settings, and also conducts HIV research in a large women’s cohort. He sees patients in clinic one day a week. Dan lives in Maryland with his wife and 4 boys. | |||
| Archive Highlight: The science of fermented foods, part 2, with Prof. Bob Hutkins | 29 Jan 2025 | 00:25:08 | |
Continuing in the series on the latest fermented food science, we are highlighting Episode 3 from our archives. The hosts continue their discussion of fermented foods with Prof. Bob Hutkins, University of Nebraska – Lincoln. Prof. Hutkins elaborates on how the microbes associated with fermented foods may confer health benefits, as well as how food scientists choose strains for fermentation. He emphasizes how the live microbes in fermented foods differ from probiotics. Before listening to this episode, it’s recommended that you check out The science of fermented foods, Part 1. Key topics from this episode:
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About Prof. Bob Hutkins: Bob Hutkins is the Khem Shahani Professor of Food Microbiology at the University of Nebraska. He received his Ph.D. from the University of Minnesota and was a postdoctoral fellow at Boston University School of Medicine. Prior to joining the University of Nebraska, he was a research scientist at Sanofi Bio Ingredients. The Hutkins Lab studies bacteria important in human health and in fermented foods. His group is particularly interested in understanding factors affecting persistence and colonization of probiotic bacteria in the gastrointestinal tract and how prebiotics shift the intestinal microbiota and metabolic activities. The lab also conducts clinical studies using combinations of pro- and prebiotics (synbiotics) to enhance health outcomes. More recently we have developed metagenome-based models that can be used in personalized nutrition. Professor Hutkins has published widely on probiotics, prebiotics, and fermented foods and is the author of the recently published 2nd edition of Microbiology and Technology of Fermented Foods. | |||
| Archive Highlight: The science of fermented foods, part 1, with Prof. Bob Hutkins | 23 Jan 2025 | 00:25:54 | |
Welcome to the first episode of our new series on the latest fermented food science. We are highlighting Episode 1 from our archives with guest Prof. Bob Hutkins, University of Nebraska – Lincoln. Prof. Hutkins wrote a popular textbook on fermented foods and has had a 40-year career in fermentation science. He shares why he ended up in fermentation science, as well as how fermented foods are made and how important live microbes are for their health benefits. Key topics from this episode:
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About Prof. Bob Hutkins: Bob Hutkins is the Khem Shahani Professor of Food Microbiology at the University of Nebraska. He received his Ph.D. from the University of Minnesota and was a postdoctoral fellow at Boston University School of Medicine. Prior to joining the University of Nebraska, he was a research scientist at Sanofi Bio Ingredients. The Hutkins Lab studies bacteria important in human health and in fermented foods. His group is particularly interested in understanding factors affecting persistence and colonization of probiotic bacteria in the gastrointestinal tract and how prebiotics shift the intestinal microbiota and metabolic activities. The lab also conducts clinical studies using combinations of pro- and prebiotics (synbiotics) to enhance health outcomes. More recently we have developed metagenome-based models that can be used in personalized nutrition. Professor Hutkins has published widely on probiotics, prebiotics, and fermented foods and is the author of the recently published 2nd edition of Microbiology and Technology of Fermented Foods. | |||
| Gut microbes and other drivers of inflammation in Parkinson’s disease, with Prof. Malú Tansey PhD and Dr. Andrea Merchak PhD | 09 Jan 2025 | 00:30:59 | |
This episode features Prof. Malú Tansey PhD and colleague Dr. Andrea Merchak PhD from the University of Florida, USA, discussing neuroinflammation and the role of gut microbes in Parkinson’s disease (PD) and other neurodegenerative diseases. “Inflammaging” tends to occur as aging progresses, but the links that have been made between the gut and the brain in PD have led their group to the hypothesis that PD may be an age-acquired autoimmune condition. Genetic factors are relevant, although not everyone with PD has the predisposing genes. Those with a certain genetic mutation have a different immune phenotype from normal. Furthermore, the gut microbiota influences the immune system and the inflammatory environment within the body, with some metabolites known to cross the blood-brain barrier and influence the immune cells of the brain. Currently the group is focusing on using the gut microbiome, blood, and colonic biopsies to gain insights into the brain. A combination of diet and probiotics is promising as an intervention to prevent neurodegeneration as people age. Episode abbreviations and links:
About Prof. Malú Tansey PhD: Malú Gámez Tansey, Ph.D. is the Norman and Susan Fixel Chair in Neuroscience and Neurology and former Director of the Center for Translational Research in Neurodegenerative Disease at the University of Florida. Her lab focuses on the role of inflammation and immune system responses in brain health and neurodegenerative disease, with particular focus on central-peripheral neuroimmune crosstalk and the gut-brain axis, with the long-term goal of developing better therapies to prevent and/or delay these diseases. Dr. Tansey obtained her B.S/M.S in Biological Sciences from Stanford University and her Ph.D. in Cell Regulation from UT Southwestern followed by post-doctoral work in neuroscience at Washington University. As head of Chemical Genetics at Xencor, she co-invented novel soluble TNF inhibitors that have now advanced to clinical trials in Alzheimer’s disease. She returned to academia as an Assistant Professor of Physiology at UT Southwestern in 2002 and was recruited to Emory University School of Medicine as a tenured Associate Professor in 2009. After 10 year at Emory and rising to the rank of Full Professor where she earned several mentoring awards from students and faculty for her efforts in championing early-stage investigators, women and other under-represented groups in STEM, she was recruited to the Department of Neuroscience in the College of Medicine at the University of Florida, where she served on the executive committees for the McKnight Brain Institute and the Fixel Institute for Neurological Diseases. She will be moving to the Stark Neuroscience Research Institute at Indiana University in Indianapolis in January of 2025 as the first Director of Neuroimmunology Research and Executive Associate Director of Education at the Stark NRI. About Dr. Andrea Merchak PhD: Andrea Merchak, Ph.D. is a Gator Neuroscholar Postdoctoral Associate at the University of Florida. She obtained her B.S. at Centre College with a focus on behavioral neuroscience and her Ph.D. from the University of Virginia. There, her thesis work explored the link between the gut microbiota and the brain in mood disorders and multiple sclerosis. Her current work explores the relationship between gut health and genetic predispositions for neurodegeneration. She has received recognition for her work through the Young Scientist Award from the International Prebiotics, Probiotics, and Gut Microbiome Conference, the Outstanding Graduate Student Award from the University of Virginia, as well as a track record of funding from the NIH. She will be moving to the Stark Neuroscience Research Institute at Indiana University in Indianapolis in March of 2025 as an Assistant Professor of Neurology. | |||
| Using a microbiota-gut-brain axis on a microfluidic chip to gain insights into neurodegenerative diseases, with Prof. Kerensa Broersen PhD | 12 Dec 2024 | 00:29:12 | |
This episode features Prof. Kerensa Broersen PhD from University of Twente in the Netherlands, speaking about using an innovative model of the microbiota-gut-brain axis to learn about neurodegenerative diseases such as Parkinson’s disease. Prof. Broersen says that while clinical studies are applicable to human health and animal models have great physiological complexity, her lab focuses on a model that’s more flexible and that allows manipulation of specific signalling events – a microbiota-gut-brain axis on a microfluidic chip. To make the brain component, they use stem cells from healthy people (from bone marrow, blood, or urine), which can differentiate into different types of cells depending on the factors they’re exposed to. They create cells that represent different areas of the brain, and can keep them alive and functional for at least 100 days. They can also represent disease processes in the model. It’s known that the gut microbiota is involved in neurological disease and may be either a cause or consequence of the brain pathology; so in this model, the scientists culture gut microbes in one microfluidic device and the brain in another microfluidic device, then connect the two. This allows them to make changes in one compartment and see how it affects the other. In this way, Prof. Broersen is aiming to understand some of the very basic mechanisms of neurodegenerative disease development and progression. Episode abbreviations and links:
About Prof. Kerensa Broersen PhD: Kerensa Broersen obtained a PhD in food chemistry from Wageningen University and Research, the Netherlands, in 2005, followed by two postdoctoral positions at the Medical Research Council in Cambridge, UK and the Free University of Brussels in Belgium, both focussing on protein aggregation in neurodegenerative disorders. She then joined the University of Twente at a tenure track assistant professor position to further investigate neurodegenerative disorders making use of neuronal cell types. Following a sabbatical at the University of California – Berkeley, in the group of Randy Schekman, Kerensa Broersen moved into the field of gut-brain communication studying the fundamentals of signaling pathways driving the intricate interaction between the intestinal microbiome, the gut and the brain. For this, she is making use of the differentiation potential of stem cells to create mini-versions of the organs involved cultured onto microfluidic devices. | |||
| Developing probiotics for neurodegenerative disease, with Dr. Alex Parker PhD | 05 Dec 2024 | 00:28:36 | |
This episode features Dr. Alex Parker PhD from Université de Montréal talking about models for studying neurodegenerative diseases. His lab makes use of the worm C. elegans, a common model organism for studying disease and aging as it has many genes in common with humans. Focusing on amyotrophic lateral sclerosis (ALS), Dr. Parker makes models that reflect some aspect of the disease – in this case, genes that are directly linked to ALS are directly expressed in the nervous systems of the worms. Then the lab screens different small molecules from drug collections to see what seems to protect the worms from neurodegeneration. In human ALS, the microbiome is a potential factor that could influence the development of disease if a genetic predisposition is present. Dr. Parker’s lab screened a collection of microorganisms and found one strain that protected the worms from progression of neurodegeneration. Simultaneously, they saw that genes involved in lipid metabolism were being altered. Their work indicates a signaling mechanism from the intestine to the nervous system turns on a protective pathway in the worms – and interestingly, feeding the worms fatty acids directly was not as effective, possibly indicating that the live microorganism is working through multiple pathways. Currently the group is testing the probiotic in mouse models and in an upcoming clinical trial examining how the lipid profile of ALS patients changes as the disease progresses. Episode abbreviations and links:
About Dr. Alex Parker PhD: Alex Parker obtained a PhD in Medical Genetics at the University of British Columbia with Dr. Ann Rose using the model organism C. elegans to study Huntington’s disease. From there he did postdoctoral training with Dr. Christian Neri at INSERM, (Paris, France) to develop drug discovery methods for trinucleotide repeat disorders. He is now a professor in the department of neuroscience at the Universite de Montreal, and a researcher at the CRCHUM. His research focuses on developing genetic models for a wide range neurodegenerative diseases with a special focus on amyotrophic lateral sclerosis to find new therapeutic strategies with translation to clinical settings. Recently his team discovered a probiotic that protects against neurodegeneration in animal models and is now part of a clinical trial for ALS. | |||