This week on Show Me The Science, Professor Luke O'Neill takes a look at the science of the gut microbiome, how the health of your gut is important for your health overall and new findings on bacteria and cancers.

This week on Show Me The Science, Professor Luke O'Neill takes a look at the science of saunas.

How does taking a sauna benefit your health and mood, and exactly how much time should you spend in a sauna?

With St Patrick’s Day just around the corner, Professor Luke O’Neill takes a closer look at the man behind the legend—and the science behind the stories. Drawing on Patrick’s own Confessio, Luke explores how the saint lived a long life, likely thanks to a mix of lifestyle and genetics. 

Could there have been two Patricks, Patricius and Palladius? Luke unpacks this theory and shares its surprising connection to the early days of Ireland’s Dublin Institute for Advanced Studies. 

He also tackles the myth of Patrick banishing snakes, explaining how the last Ice Age shaped Ireland’s landscape and wildlife. And he examines the shamrock, used by Patrick to illustrate the Holy Trinity, and its medicinal properties, from easing menopausal symptoms and asthma to treating wounds and fevers. 

It’s history, myth, and biology all rolled into one festive podcast.

You know if things had worked out differently 800,000 years ago you wouldn't be here to listen to this podcast? There wouldn't even BE podcasts which is even more shocking to comprehend. In this week's episode Luke discusses how fossil records have recently revealed that there was a big disappearance of hominids which has led them to conclude that we may not have happened!

There is no doubting that A.I is here to stay and it is here to revolutionise pretty much every aspect of our lives. There has been many concerns as to what that future will look like but in this week's episode Luke tries to allay at least some of those fears by identifying 4 major benefits of A.I.

Utilizing our own immune systems to fight cancer has always been an interesting idea to scientists, and now there's serious progress being made in this filed that could see us developing personalized treatments for the disease.

Radiotherapy, chemotherapy and surgeries are all useful treatments but a vaccine against the tumor could be much more effective without being as intrusive.

Luke explains how they might make these vaccines and gives the latest update on the clinical trials going on.

Between 1980 and 2009, the rate of twinning in the US increased by 76%, and this trend is seen across the world. Twins can be either fraternal where two eggs are fertilized at the same time, or identical where one fertilized egg splits in two. Both of these offer huge opportunities for scientists to learn about genetic traits and environmental impacts on development.

Luke explains what we've learned from twin studies and why they're so useful.

The Covid-19 pandemic may still be fresh in all our memories, but scientists are already looking ahead to the next big pandemic to allow us to prepare and get ahead of it.

A flu virus seems to be the most likely cause and in particular there is concern around the H5N1 strand which has now jumped from birds to cattle, and even a few dairy farmers. Human to human transmission is the next big warning sign which is being closely monitored.

Luke explains what we learned during the last pandemic to prevent the spread of another virus and another global lockdown.

We all have our favourite songs - The ones that remind us of childhood memories, give us a boost of energy or the ones we play to make us cry. But where did music come from and what makes us connect so strongly to it?

Luke answers these questions as well as explaining what makes some people so talented musically, and others more tone deaf.

How can we increase our life expectancy? Do we have any control over it or is it all to do with our genetic makeup? A new study into microscopic worms has revealed how their genes allow them to enter a 'dauer' state of almost hibernation during times of limited food and in doing so expand their lifespan from 2 weeks to over 2 months. Luke explains how this works and how this finding could be useful for humans.

Why did we all put our clocks forward by an hour a few weeks ago? And why will we push them back again come autumn? The historic justifications were to allow for brighter mornings in the autumn and winter and extra daylight at the end of the working day across spring and summer. But, now there's some push back on the practice and Luke explains why some think it's harmful.

Is 2024 the year we'll finally see self driving cars on our roads? While there are already some 'Robo-cabs' in service in the United States aiming to provide a 'safer' driving experience, there are still big challenges for the futuristic technology before they can be more widely rolled out. Luke gives us an update of the latest state of affairs in the world of driverless cars.

When new machinery was first invented, researchers notices that frequent users such as factory workers or typists were developing repetitive strain injuries. And, now that technology has become such a crucial part of all our lives, and we all spend hours daily with our heads tilted down at a screen they are seeing a surge of the phenomenon known as 'Tech Neck' .

Luke looks at the research into the muscle strain and offers some solutions for those suffering.

Winter sports look clean and crystalline on the surface. Snow, ice, precision, courage. But scratch that frozen surface and you find molecular biology doing quiet, mischievous work. 

In this week’s podcast, Professor Luke O'Neill takes us from the ski jump ramp to the veg aisle, via one of the strangest alleged performance hacks of the recent Winter Olympics. 

First stop: hyaluronic acid. A substance your body already makes, found in skin and connective tissue, famous for its ability to hold vast amounts of water. That’s why it appears in skin creams, dermal fillers, and treatments for sore joints — it hydrates, cushions, and plumps. 

Reports suggested some ski jumpers injected it weeks before competition to temporarily enlarge their genitals while being fitted for tightly regulated suits. If the swelling subsided by competition time, the slightly looser fabric could improve aerodynamics. In a sport decided by metres, even tiny changes in airflow can translate into significant gains. That raises an awkward question: if it enhances performance without acting like a traditional drug, does it still count as doping? 

Then there’s broccoli. Many athletes were reportedly using concentrated broccoli juice supplements. Broccoli and other cruciferous vegetables contain isothiocyanates, compounds linked to anti-inflammatory effects. In high-impact, repetitive sports, reducing inflammation may aid recovery between events. 

There’s early research exploring whether these molecules could help in conditions like ulcerative colitis and multiple sclerosis. But while broccoli is unquestionably nutritious, robust clinical evidence for performance-boosting concentrated extracts is limited. A single shot can equal several large heads of broccoli — and tastes predictably grim. 

Winter sports may look like poetry in motion. Underneath, it’s chemistry in motion. And sometimes, it’s broccoli. 

Why does the immune system differ from person to person? Why do some people seem more resistant to infections or viruses than others? New research has sought to answer these questions, and in the process shown the impact of smoking on your immune system and in particular the effects on the adaptive immune response.

Luke takes us through the new research and explains how smoking can turn off some of our internal defense systems.

An Irish research team has just had a breakthrough on their research into Long Covid. Luke recaps what we already know about the condition which causes brain fog and fatigue in roughly 1 in 3 patients infected with Covid-19.

He also explained what the brain blood barrier may have to do with it, and what potential treatments or preventative measures may come from this research.

Elon Musk's latest venture 'Neuralink' which aims to place a chip within the brain of a human has shown 'promising neural spike detection'. This means that down the line a brain implant could pick up on our thoughts and communicate them directly to a computer, allowing our thoughts to be sent as text messages without ever picking up a phone, or to move a prosthetic limb with ease.

Luke takes us through the latest developments in the world of brain implants and offers other examples of their existence already in circulation such as cochlear implants.

Could Viagra an erectile dysfunction drug, have a second function working to prevent Alzheimer's?

Luke recalls how the drug was initially created to treat angina before it's accidental side effect made it a huge success for Pfizer. He explains how the drug works and why researchers are looking at it more closely now.

Are you a night owl looking to become more of a morning person?

There are lots of health benefits to waking up earlier but is it even possible to become a morning lark if it's against your nature? Luke explains the role our genes and even the Neanderthal's play in our chronotypes.

He also offers some tips for changing your sleeping patterns and explains how your sleep patterns alter over time.

How many times should you shower each week? Or should we shower at all? The average changes depending on location and culture, ranging from 12 per week in Brazil to 5 per week in the UK.

We all know the obvious risks of not showering enough, but showering too much can also have it's downsides like overly dry skin and increased risk of infection. Luke explains how showering affects our body and why our bodies make things like sebum and sweat that we wash away.

Multiple sclerosis also known as MS is an auto immune disease that causes symptoms such as muscle weakness, pins and needles, double vision, poor balance and fatigue. There are various factors that affect your chances of developing MS including genetics, geography and according to a new study exposure to the Epstein–Barr virus. Luke explains the thought behind this new research and how it could help find a preventative measure for MS.

Although it might seem like it was just yesterday, it's already been 4 years since the first fatality as a result of Covid-19. Luke takes us back to what we knew then and shows just how quickly science reacted to the disease with things like vaccines and therapeutic remedies. He also asks what we have learned from the last 4 years and the most important question of all - Are we ready for the next pandemic when it comes along?

We might understand what causes an itch in theory: an insect bite, a healing wound, a poisonous plant. But, where does the urge come from? And what's going on within our bodies to make us scratch? Luke explains the science and the latest research which might finally result in remedies for those suffering with issues like dermatitis or eczema.

A dark tunnel with a light at the end, family and friends who have already passed on, or a religious figure are all common visions following near death experiences. But, what really happens when our hearts stop? And where do these visions come from? A new study of resuscitated patients in 3 hospitals across the world sought to answer these questions and in this episode Luke explains their findings.

Cholesterol has a reputation problem. We tend to think of it as the enemy, but your body makes it for a reason. Every cell membrane relies on it, and it’s the building block for key hormones like oestrogen, progesterone, and corticosteroids. You also get cholesterol from your diet. The real issue isn’t cholesterol itself — it’s where it ends up. 

In the early 1900s, pathologists examining people who died from heart attacks found arteries lined with cholesterol-rich plaques, complete with visible crystals. By the 1950s and 60s, research confirmed that high cholesterol in the blood is a major risk factor for heart disease. When plaques build up, they trigger inflammation and clotting, potentially cutting off blood supply to the heart. 

Cholesterol doesn’t travel freely in the bloodstream — it’s packaged into tiny particles called lipoproteins. These act like delivery vehicles, carrying cholesterol around the body. Drugs such as statins reduce cholesterol production and improve its clearance, saving millions of lives. Exercise, diet, and blood pressure control are also critical, especially since high blood pressure and high cholesterol together significantly increase risk. 

But there’s more to the story. Around one in 250 people have inherited conditions that leave them with very high cholesterol levels. And as listener Tara asked in her email to the podcast, what about Lipoprotein little a — or Lp(a)? 

Lp(a) is a specialised lipoprotein that can increase inflammation and clot formation. Elevated levels are linked to a greater risk of heart attack — even if your standard cholesterol numbers look normal. That means measuring total cholesterol alone may not tell the full story. 

On this week’s podcast Professor Luke O’Neill explores why cholesterol is essential, how it becomes dangerous, and why particles like Lp(a) could be key to identifying hidden heart risk. 

Have a science question you’d like answered? Email laoneill@tcd.ie and it might feature in a future episode. 

As we begin a new year bound to bring with it a multitude of exciting scientific discoveries, Luke takes stock of the year just gone and all of the exceptional breakthroughs from 2023. It was a big year for science, as aging was reversed, Alzheimer's slowed, and the true number of steps needed for health revealed. AI has already had a big impact on science and this year was no different, Luke talks us through some of the highlights, while waiting to see the inevitable role it will play in the scientific advancements of 2024.

Proteins are the work horses of life and the building blocks for everything from enzymes and antibodies to hormones and of course muscles. Many gym goers add additional protein to their diet in order to build extra muscle. Luke explains how your body build muscles and the benefits of protein supplements, as well as exploring what is actually in them and asking if there is really science behind the claims that they help to build muscle.

Frankincense and myrrh are probably most famous for being two of the three gifts brought by the Wise Men to the newborn baby Jesus, along with gold. But, they are also ancient herbal remedies. The salve extracted from the myrrh tree was used to heal wounds while frankincense had its own uses such as in religious ceremonies and as a perfume. Luke explains why these were so valuable in ancient times, how they worked to suppress pain, and he explains how they could inspire modern day medicines.

Our immune system is constantly working hard to protect us from infection and disease, but try as it may it has always struggled to defend our bodies from tumours and cancerous growths. For years, scientists have been looking for a way to stimulate the immune response more effectively in the fight against cancer. Luke takes us through the various successful and unsuccessful attempts to do just this as well as the new drugs that are reducing the death rates from melanoma.

We all know that our muscles get tired after we use them, but what about our brain? Does it need rest too after strenuous use? Luke delves into the world of mental exhaustion to explain what we know, as well as the latest breakthroughs and how they might lead to cures for Alzheimer's and allow us to focus for longer.

Did you know that being a heavy metal music fan might actually help the climate crisis - Or at the very least that's one of the aims of the musical genre where the lyrics frequently call out inequality and problems within society. Listening to the distorted guitar riffs and stylized vocals can also help improve mental health, while head banging along has it's own benefits too, provided you don't get too into the music and hurt yourself! Luke explains the science behind the musical genre's surprising benefits.

Everyone loves a trip away, but when you're afflicted by motion sickness it can make the journey and any necessary travel plans very arduous - Be they on a plane, in a car or onboard a ship. Luke explains the causes of motion sickness, the various symptoms and the breakthrough that means a cure might not be too far away!

The winners of the 2023 Nobel Prize for Medicine or Physiology have been announced! And the coveted prize has been awarded to two scientists, Katalin Karikó and Drew Weissman for their research on how to use RNA in a vaccine. Luke tells us about the winners, and talks us through their work as well as it's significance for the world of science and medicine.

Could bacteria and viruses cause psychiatric disorders?

This week Luke receives a request from a concerned grandmother and is happy to seek out the answers she needs. He explores a fascinating new arena of medical science, and tell us about work being done to develop therapies, and even vaccines, to combat major psychiatric disorders in children.

Artificial intelligence is a new frontier for scientists and researchers to explore. Luke talks us through some of the applications of the new technology, including as an educational tool, as a way of filtering online hate, and even to speed up the development of new drug therapies. He also addresses some of the concerns around the proliferation of AI and explains why we should embrace it.

Why do we sweat? And what secrets does it hold about our bodies? On this week’s podcast, Professor Luke O'Neill dives into the fascinating science of sweat. From keeping our body temperature in check to signalling stress and even potential mate selection, sweat is far more than just water and salt. 

The podcast explores how sweat is made by specialized eccrine glands, originating from plasma in our blood, and why humans are among the sweatiest animals on the planet. Luke explains how the average adult can produce up to four litres a day, and why staying hydrated is crucial. 

But there’s more: stress, exercise, and climate all change how and why we sweat. Sweat itself is odorless, but bacteria, lactic acid, and urea can create the smells we associate with adolescence, gyms, and armpits. And surprisingly, sweat contains proteins that fight bacteria, hinting at a role in our body’s natural defence. 

Could sweat one day be a diagnostic tool for disease? Why do identical twins sweat the same amount? And could it even act as a pheromone signal? Professor O’Neill explains all this and more, in a conversation sparked by a listener question from Siún. 

If you want to ask Luke your own science question, email him at: 

📧 laoneill@tcd.ie 

Aquamation is a new alternative to traditional burial or cremation after a loved one has passed away. The process involves exposing the remains to a mixture of a strong alkali and water which eventually dissolves away the remains. Luke explains how it works and why it's better for the environment than the traditional ways of handling a remains.

Pollen, shellfish, nuts, cats, penicillin - The list of allergens is never ending. But, what exactly is an allergy and why do certain people's bodies react so strongly to seemingly harmless things? Luke explains what's happening internally during an allergic reaction and updates us on the latest scientific research that might lead to a cure.

The Earth formed 4.5 billion years ago and relative to that human life, and even life in general is a considered quite a new phenomenon. But, where exactly did life come from? And how did we eventually evolve to where we are today? Luke brings us right back to the start and takes us through the origins of life as we know them.

A colony on Mars is the next big step in space exploration. But, with such a long journey ahead of them, in such a confined area, how does the team of astronauts get chosen? Luke explains the science and psychology behind choosing the team and their motto - 'Leave the jerks at home.'

A mysterious serpent that lives beneath the dark waters? A hoax? An abnormally large eel? There are many theories about the existence, or not, of the Loch Ness Monster. Now, the largest ever study of the murky lake has taken place as scientists search for a definitive answer. Luke takes us through the study, and the theories that inspired it.

The vagus nerve is the electrical superhighway of our nervous system - But just what does it do? And could triggering it be one potential solution to issues as wide ranging as obesity and depression to rheumatoid arthritis and Crohn's disease?

Luke takes us through the latest research into the vagus nerve and explains how simply zapping it with electricity or triggering it through the ear might have positive effects.

We've all heard that we should be getting 10,00 steps a day - But is this backed up by science? How many steps do we actually need to see benefits for our health? Luke takes us through the latest science that suggests less than half of that figure may be enough to reduce your risk of dying.

Our genome is the recipe that makes us who we are and the day the human genome was finally mapped out was one of great celebration for scientists across the world. Yet, we still do not know what one fifth of those genes do. But, as Luke explains, thanks to new research some of these gaps in our knowledge are being filled.

Weather forecasts are famously imperfect, but the science behind them is far cleverer than we usually give it credit for. 

In this week's podcast, Professor Luke O’Neill explores how weather forecasting works, and why floods remain one of the hardest things to predict. Luke isn’t a meteorologist — although he did briefly consider it in college — but too much physics put him off. Still, he’s an ideal guide to the basics because the weather is really about a few core ideas behaving badly. 

At its heart, forecasting comes down to temperature, air pressure, humidity, sunlight, and the way air flows like a fluid. Air moves from high to low pressure, dragging wind and weather systems with it. Add water vapour into the mix and things get interesting very quickly. 

People have been trying to predict the weather for hundreds of years, using almanacs, folklore, and observation. It was never perfect, but it mattered hugely to farmers and sailors. Rain, in particular, remains tricky. Moist air rises, cools and condenses into clouds — but rain doesn’t just appear. It needs tiny particles like dust, sea salt, or pollen to form droplets, and those microscopic details are hard to pin down. 

Today’s forecasts rely on satellites, radar, weather balloons, and ground stations, all feeding data into powerful computer models. Those models keep improving, and artificial intelligence is now helping to sharpen predictions. 

Flooding is even more complicated. It’s not just about how much rain falls, but how fast it falls, how long it lasts, and where it lands. Soil type, vegetation, evaporation, and urban concrete all matter. Forests and wetlands act like sponges, while cities can make flooding worse — something Ireland knows well after decades of building on flood plains. 

Some countries lead the world in flood modelling, but nowhere reliably predicts flash floods. Luke argues that weather is a brilliant way to teach science, and that we already know how to reduce flood risk. The challenge now is acting on that knowledge and getting on with it.