Humans have been heading into space to explore beyond earth for decades already. But when we head beyond our own atmosphere, what happens to our immune system?

In this episode, we dive into astro-immunology: a sub-field of immunology that focuses on how our immune system responds to spaceflight.

Let's dive in!

Key reference:

Winer D.A. et al. Astroimmunology: the effects of spaceflight and its associated stressors on the immune system. Nat Rev Immunol (2025). https://doi.org/10.1038/s41577-025-01226-6

The summer of 2016 was warm in Siberia. So warm that the permafrost melted more than usual… releasing a dangerous microbe out onto the surface.

In this episode, we dive into this historical example of an old microbe emerging from the permafrost, talk about how microbes can survive in the deep cold… and idee should be worried about what else might emerge.

Have you ever wondered why you need some vaccinations more often than others?

Listen in to Merel and Alex to find out how vaccines train the different specialized cells of your immune system to fight viruses... And how viruses are constantly fighting back.

Welcome to the Microbial Mondays podcast! In this first episode, your hosts Merel Sijbranda and Alex Cloherty introduce themselves, let you know what you can expect from this podcast, and then dive into the science by explaining the focuses of our own PhD projects.

Listen in to find out about the work we did (Alex) or are doing (Merel) to better understand how your immune cells - which all have different jobs - band together to defend against threats ranging from HIV to SARS-CoV-2 and beyond.

Have you ever wondered how our immune system finds the balance in attacking invading viruses and bacteria that try to enter our bodies, but not attacking our own body cells?

The groundbreaking discoveries concerning this topic, called 'peripheral immune tolerance', by Mary E. Brunkow, Fred Ramsdell and Shimon Sakaguchi were awarded the Nobel Prize in Physiology or Medicine 2025! It tells us a lot about how the immune system functions in health and disease!

In this episode, we dive into:

• the discoveries that led to winning this year's Nobel Prize,
• Mary E. Brunkow, Fred Ramsdell and Shimon Sakaguchi's journey to get to these discoveries,
• what impact these discoveries have had in the past, still have now, and will have in the future!

This podcast episode was created based on the Popular Science Background and Scientific Background published on nobelprize.org . If you are interested in learning more, read here: https://www.nobelprize.org/prizes/medicine/2025/press-release/

Welcome to our Halloween special!

Once your heart stops, what happens to all of the microbes that call your body home?

Tonight, we explore the silent cities left behind when we die. Scientists call this the necrobiome: the community of microbes that thrive on and around decomposing bodies.

In this episode we explore how microbes take over our bodies after death, the impact that decomposing bodies can have on the environment around them, and take a look at how microbial activity can even help forensic scientists estimate time of death.

Let's dive into this spooky topic together!

More Reading & Sources:

• Necrobiome framework for bridging decomposition ecology of autotrophically and heterotrophically derived organic matter, Benbow et al. 2018
• A conserved interdomain microbial network underpins cadaver decomposition despite environmental variables, Burcham et al. 2024
• Microbial community coalescence and nitrogen cycling in simulated mortality decomposition hotspots, Keenen et al. 2023

• BBC: Rewilding death: The plan to restore the necrobiome

Where did SARS-CoV-2 come from?

In this episode of Microbial Mondays, we unpack the findings from the WHO’s Scientific Advisory Group for the Origins of Novel Pathogens (SAGO)’s recent report. We revisit key theories, from a natural spillover event involving bats or intermediate hosts, to the lab leak hypothesis—and discuss why neither can be dismissed outright.

Join us as we explore what’s known, what’s missing, and why uncovering the virus’s origins matters for preventing future pandemics.

More reading

We covered this topic back in a blog series in 2021:

• Part 1: ​https://www.microbialmondays.com/post/lab-leaks-and-affinis-excrement-or-how-a-scientist-thinks
• ​Part 2: https://www.microbialmondays.com/post/where-did-the-virus-come-from-part-ii

Read the SAGO report: https://www.who.int/publications/m/item/independent-assessment-of-the-origins-of-sars-cov-2-from-the-scientific-advisory-group-for-the-origins-of-novel-pathogens

Hippocrates said, “let food be they medicine.” Was he right?

In this episode, Alex and Merel dive into this question from an immunological point of view. Join is for a balanced take on the links between diet, health, and the immune system, in which we explore the evidence on if different diets can impact the functioning of our immune system — and if so, how.

A hint? Our gut microbes may play a role 🦠

This episode was produced by Alex Cloherty, Merel Sijbranda, and Eric Sala Solé, and edited by Eric Sala Solé.

Have you ever wondered how the immune system differs in men versus women?

For instance, did you know that:

• Men get more viral, bacterial, parasitic and fungal infections, for example HIV and tuberculosis
• Women are more prone to develop autoimmune diseases. For example, for an autoimmune disease called lupus, 9 out of 10 patients are women
• Women have stronger antibody responses to vaccination, and antibody responses to seasonal influenza vaccines are consistently at least twice as strong in women than men
• Men show an almost twofold higher risk of death from malignant cancer than women.

In this new episode Alex and Merel discuss potential explanations for these facts, and the role for the immune system in these differences between men and women.

In this episode we try to speak to the broad diversity of sex and gender in humans where possible and where the existing research permits. We hope to see increasing immunology research that captures this diversity in the future!

How can microbes help us to “survive the next century without a wrenching global catastrophe’?

This episode is inspired by a book called The Wizard & The Prophet, by Charles C Mann. It’s all about two different ways that scientists tend to view the challenge that humanity must face in order to survive — and maybe even thrive — on earth in the future.

In this episode, we take a microbial view. First, we focus in on one story about how microbes can help from the ‘prophet’ perspective – working with microbes to preserve ecosystems. Then, we dive into a story from the ‘wizard’ perspective, and discuss how we can leverage microbes as a futuristic technology.

Whether you're more of a 'wizard' or a 'prophet', we hope we'll convince you of one thing: that the future will be microbial!

References

1. Mann, C. C. (2019). The wizard and the prophet: two remarkable scientists and their dueling visions to shape tomorrow's world. Vintage Books.
2. Sosa-Hernández MA et al. Subsoil arbuscular mycorrhizal fungi for sustainability and climate-smart agriculture: A solution right under our feet? Front Microbiol (2019). doi:10.3389/fmicb.2019.00744
3. Nihart AJ et al. Bioaccumulation of microplastics in decedent human brains. Nat Med (2025). https://doi.org/10.1038/s41591-024-03453-1
4. Li T et al. Breakdown of polyethylene therepthalate microplastics under saltwater conditions using engineered Vibrio natriegens. AIChE J (2023). doi:10.1002/aic.18228
5. Yoshida S et al. A bacterium that degrades and assimilates poly(ethylene terephthalate). Science (2016). doi:10.1126/science.aad6359

Microbes are living things, like us - they live on and in and around us. As well as learning more and more how we co-live with them, scientists have now also figured out how to use microbes as tools.

In this episode,  Alex and Merel explain one way in which microbes - in particular yeast, a type of fungus - can be used as a tool for medicine. We break down a scientific study in which scientists experimented with using yeast as a way to deliver cancer therapeutics to the right part of the body. The idea was to use yeast as a sort of mobile, mini-factory for producing the medicine, so that the medicine could be delivered at the right place at the right time. Interesting, right? Let's dive in!

Citation for the paper we discuss:

Rebeck et al. A yeast-based oral therapeutic delivers immune checkpoint inhibitors to reduce intestinal tumor burden. Cell Chem Biol. 2025 Jan 16;32(1):98-110.e7. doi: 10.1016/j.chembiol.2024.10.013. Epub 2024 Nov 20. PMID: 39571582; PMCID: PMC11741927.

Have you ever come across a stick insect? They look exactly like tree branches, blending in perfectly with their surroundings as a strategy for survival. By hiding in plain sight, they avoid detection by predators.

Just like stick insects survive by blending in with their surroundings, viruses and bacteria can do the same to avoid our immune systems and survive in our bodies. But when microbes mimic us, they may inadvertently mess with our immune systems. Researchers suspect that it could even trigger the development of autoimmune diseases.

Listen to this episode to understand how microbes can mimic humans to hide from our immune systems - and the unexpected consequences this can have.

In the last episode of Microbial Mondays, we covered what happens to our immune systems during space flight… but what about the microbes we bring with us?

This month, join us in exploring how flying into space can impact microbial life from earth!

Main publication discussed:

Wilson et al., Space flight alters bacterial gene expression and virulence and reveals a role for global regulator Hfq, Proc. Natl. Acad. Sci. U.S.A. 104 (41) 16299-16304, https://doi.org/10.1073/pnas.0707155104 (2007).

In the last years, especially when the first HPV vaccine came out in 2006, we have heard a lot of commotion around this HPV vaccine and HPV’s link to cancer.

In today’s episode, we share the story of how scientists discovered the link between HPV and cancer, and how the HPV vaccine works.