Inside Matters

Can Your Microbiome Rewrite Your Immune System's Food Allergies? Food allergies can be devastating. For families managing severe reactions, every meal carries risk, and even one mistake can have fatal consequences. But what if we could change the underlying biology rather than just manage avoidance? Dr James McIlroy explores a fascinating new study showing that faecal microbiota transplantation might help the gut relearn that foods like peanuts aren't a threat. The research points to an elegant mechanism: donor bacteria reshape bile acid metabolism, which then restores regulatory immune cells that suppress allergic responses. This episode reveals why the small intestine is critical to immune tolerance, how microbial metabolites influence what your immune system does and doesn't attack, and why owning a dog in early life might actually matter for allergy development. We're early in the evidence, but the signal is compelling.   00:00 Food Allergy Nightmare 00:43 The Real Risk Numbers 01:52 Beyond Avoidance 02:57 Why Small Bowel Matters 04:52 FMT Peanut Trial Setup 05:54 Results and Caveats 07:12 Bile Acids and Tregs 09:56 Mouse Proof of Mechanism 11:41 Dogs and Early Exposure 13:17 What Comes Next

Professor Alexandra Johnstone joins Dr James McIlroy to explore what makes us hungry, what helps us feel full, and why healthier choices are rarely a matter of willpower alone. A conversation on chrononutrition, protein, food inequality, GLP-1 medicines and the future of public health. The big idea: Our bodies, habits and surroundings all influence how we eat. Better health therefore needs more than individual resolve: it needs practical advice, supportive environments and policies that make nourishing food easier to choose. Breakfast, body clocks and the timing of food Is breakfast really the most important meal of the day? Professor Johnstone’s answer is an emphatic yes—but not because breakfast has any magical property. Her research focuses on chrononutrition: the relationship between what we eat, when we eat it and the body’s roughly 24-hour circadian rhythms. The timing of the largest meal may not dramatically alter how much energy the body burns, but it can change how eating feels. A larger breakfast appears to help people feel fuller and may make a calorie-reduced diet easier to follow. The body also tends to be more sensitive to insulin earlier in the day. There is no universal clock-time definition of breakfast. A useful way to think about it is the first meal within two or three hours of waking. Fasting is a tool, not a loophole Intermittent fasting and time-restricted eating can be useful for some people, but they are behavioural strategies rather than shortcuts around energy balance. Professor Johnstone favours including the morning meal and offers the practical reminder: eat breakfast like a king and dine like a pauper. What does a healthy breakfast look like? From traditional cooked breakfasts to fortified cereals, the conversation explores nutritious options while highlighting the difference between everyday foods and occasional treats. Hunger and appetite are not the same thing A clear and helpful distinction between true hunger and appetite, and why reducing eating behaviour to willpower alone is so misleading. Why protein is filling Protein is the most satiating nutrient. The episode dives into the science of satiety, the importance of whole-food sources, and why solid protein tends to be more filling than liquid forms. Fibre does a different—but equally important—job While protein excels at satiety, fibre is essential for gut health. The trade-offs and benefits of both are explored. The obesity paradox and fixing the food environment Obesity is strongly patterned by inequality. The discussion covers food insecurity, the obesogenic environment, retail promotions, and the need for policy changes that make healthier choices easier. Ultra-processed food: a debate that needs more evidence A nuanced look at ultra-processed foods, their role in the diet, and what the current science can – and cannot yet – tell us. GLP-1 medicines: powerful treatment, unanswered questions The benefits, limitations, and challenges of GLP-1 medications, including muscle preservation, long-term use, and access/inequality concerns. Alcohol, Mediterranean patterns and the value of connection The role of social connection, shared meals, and balanced enjoyment of food and drink. A practical takeaway: build patterns, not perfection Realistic, compassionate advice for building sustainable eating habits without shame or moral judgment. What comes next Professor Johnstone shares her vision for the future of nutrition science, including better guidance for shift workers, updated protein recommendations, and improved food systems. About the Conversation In this episode of Inside Matters, host Dr James McIlroy speaks with Professor Alexandra Johnstone, Chair of Nutrition at the University of Aberdeen. Timestamps: 00:00 Meet Professor Alex Johnson 01:53 Breakfast and Chrononutrition 05:13 Fasting and Eating Windows 07:59 What Makes a Healthy Breakfast 10:42 Hunger vs Appetite Explained 15:49 Protein and Satiety Science 18:20 Obesity Paradox and Poverty 19:53 Fixing the Food Environment 23:11 Gut Brain Axis and Weight Defense 27:06 Obesogenic Retail and Policy Changes 31:16 Alcohol Mediterranean Diet and Blue Zones 38:05 Why Protein Fills You Up 38:52 Protein Satiety Mechanisms 39:32 Amino Acids vs Whole Protein 40:48 Liquid Meal Replacements 43:49 Ultra Processed Food Debate 50:41 Scotland Diet Reality Check 52:37 Red Meat and Cancer Risk 53:47 GLP-1 Weight Loss Challenges 55:07 Microdosing and Inequality 01:04:19 Muscle Loss and Nutrition 01:05:50 Fibre Deep Dive 01:08:21 Sweeteners and Microbiome 01:10:44 Future Vision and Wrap Up  

For years, the spotlight in microbiome research has been firmly on the gut. We’ve learned that diversity there is generally a good thing—linked to resilience, health, and better outcomes. But what if one of the most important microbiomes in the body follows completely different rules? In a recent conversation, Dr James McIlroy sat down with Professor David MacIntyre, Director of the Robinson Research Institute, to explore a rapidly emerging field: the female reproductive tract microbiome. What they uncovered challenges many assumptions—and could transform how we think about pregnancy, birth, and early life health.   00:00 Show Returns 01:34 Why Reproductive Microbiome 05:15 Low Diversity Health 09:24 Lactobacillus Protection 12:06 Human Uniqueness 14:17 Population Differences 16:31 Oral Probiotics Myth 19:25 Vaginal Biotherapeutics Trial 22:11 Host Immune Response 27:03 Dysbiosis Triggers 30:42 Microbiome and Preterm Birth 33:06 Labor Inflammation Pathways 38:10 Pregnancy Microbiome Shifts 39:11 Screening and Group B Strep 40:57 Microbiome Screening Potential 42:06 Global Data Predictive Signatures 43:23 Limits of Current Risk Tools 45:30 Point of Care Profiling Vision 46:50 Swab Mass Spec Barcoding 48:27 Composition Versus Host Response 49:58 Metabolic Dark Matter 52:13 Beyond Bacteria, Viruses, and Fungi 55:48 Vaginal Probiotic Trials 57:39 Phase Two Trial Endpoints 01:01:28 Vaginal Microbiome Transplants 01:05:46 Birth Seeding After C Section 01:10:57 Do Vaginal Strains Persist 01:14:05 Ten-Year Personalised Medicine 01:17:45 Wrap Up And Where To Find   A Different Kind of Microbiome When we talk about the gut microbiome, diversity is often considered a hallmark of health. The reproductive tract? It’s the opposite. In healthy women, this environment is typically: Low in diversity Dominated by one key group of bacteria: Lactobacillus This might sound counterintuitive—but it’s by design. Why low diversity works here Certain Lactobacillus species—particularly Lactobacillus crispatus—play a protective role by: Producing lactic acid, keeping the environment acidic (around pH 4) Preventing harmful microbes from growing Blocking pathogens from attaching to tissue Producing antimicrobial compounds In short, they create a stable, protective ecosystem. When this balance is disrupted and diversity increases, it’s often linked to: Infection Inflammation Poor reproductive outcomes A Unique Human Feature One of the most surprising insights? Humans are the only species known to have a Lactobacillus-dominated reproductive microbiome. Even our closest primate relatives don’t share this feature. That suggests this system evolved relatively recently—and likely offers a meaningful biological advantage, particularly in pregnancy and childbirth. The Link to Preterm Birth Preterm birth—defined as delivery before 37 weeks—affects around 1 in 10 pregnancies globally and remains a major medical challenge. The microbiome appears to play a key role, particularly in early preterm births. What’s happening biologically? In a healthy pregnancy, labour is triggered by controlled, sterile inflammation This process helps: Break the membranes (waters) Open the cervix Initiate contractions But if inflammation starts too early, it can trigger premature labour. Where the microbiome fits in A Lactobacillus-dominant microbiome helps: Keep inflammation low Maintain a strong mucosal barrier Reduce infection risk When this balance is lost: The environment becomes less acidic Inflammatory molecules increase The barrier weakens Risk of infection—and preterm labour—rises Once inflammation starts, it’s very difficult to switch off. That’s why prevention is so important. What Disrupts the Balance? Several factors can shift the microbiome away from its protective state: Antibiotics (even when used for unrelated infections) Sexual transmission of bacteria Hormonal changes Menstruation Hygiene practices like douching Even small changes in pH or environment can allow harmful bacteria to gain a foothold. Can We Predict Risk Earlier? One of the most exciting areas of research is using the microbiome as a predictive tool. Scientists are working towards: Identifying microbial “signatures” linked to higher risk Measuring both: Which microbes are present How the body is responding to them New technologies can now analyse a simple swab and generate a metabolic “barcode” in minutes—potentially enabling rapid screening. The long-term vision? Routine testing that identifies at-risk pregnancies early—before symptoms appear. Can We Change the Microbiome? If we can measure it, can we fix it? 1. Oral probiotics: limited impact Despite widespread marketing, there’s little evidence that oral probiotics reliably reach or colonise the reproductive tract. They may have indirect benefits—but they’re not an efficient delivery method. 2. Targeted vaginal probiotics More promising is direct delivery of beneficial bacteria. A recent clinical trial explored a vaginally delivered strain of Lactobacillus crispatus: Safe and well tolerated in pregnancy Successfully colonised the microbiome Showed early signs of reducing preterm birth risk A larger, definitive trial is now underway in the UK. 3. Microbiome transplantation Inspired by faecal transplants, researchers are exploring vaginal microbiome transplants. Early studies show potential—but challenges remain: Regulation Standardisation Safety at scale For now, this remains experimental. The First Microbial Gift: Birth The microbiome’s role doesn’t stop at pregnancy. During vaginal birth, babies are exposed to their mother’s microbes—an important early “seeding” event. Babies born via caesarean section: Have different early microbiomes May face higher risks of certain conditions (e.g. allergies) There’s growing interest in “vaginal seeding” for C-section babies—but: Evidence is still emerging Safety concerns remain It’s not yet standard practice A Shift Towards Personalised Pregnancy Care Looking ahead, this field is moving towards a precision medicine approach. Instead of treating all pregnancies the same, we may soon: Assess individual microbiome profiles Measure immune responses Identify personalised risk Apply targeted interventions early—or even before conception The goal? Not just preventing complications—but optimising pregnancy from the start. Why This Matters This isn’t just about microbes—it’s about long-term health. By improving the maternal microbiome, we may: Reduce preterm birth Improve newborn outcomes Influence lifelong health trajectories As Professor MacIntyre puts it, we’re on the cusp of a major shift—from reacting to problems to preventing them before they begin.  

Dr Debra Silberg joins Inside Matters for a deep, wide-ranging conversation on gut health, drug development, and the future of microbiome therapeutics. Dr Silberg is the Chief Scientific Officer at Beyond Celiac, a former global clinical leader at Shire/Takeda and AstraZeneca, and one of the most respected figures in GI medicine and microbiome science. In this episode, we explore: • How she moved from basic science to medicine to pharma leadership • Why the GI field needed so much research — and how it transformed • The real science behind ulcers, H. pylori, and the Barry Marshall story • What she teaches in her popular “Understanding Your Gut” course • Prebiotics vs probiotics — what actually matters • The truth about gluten, celiac disease, gluten sensitivity and rising incidence • The microbiome’s role in inflammation, autoimmune disease, mental health & IBS • Whether microbiome drug development is finally turning a corner • Why the gut–brain axis may be the most exciting frontier in medicine Dr Silberg also shares insights from her work with Finch Therapeutics, her role at Beyond Celiac, and her experience advising the team at Biotics. If you’re interested in gut science, the microbiome, diet, or how modern medicines are built from the ground up, you’ll get a huge amount from this conversation. Be well, trust your gut — and thanks for listening. 00:00 Introduction to Dr Debra Silberg 00:54 Dr Silberg's Career Journey 02:26 Insights on Gut Health and Microbiome 04:05 Understanding GI Diseases and Treatments 07:41 The Role of Diet in Gut Health 15:59 Celiac Disease and Gluten Sensitivity 25:04 Exploring the Microbiome 27:43 Exploring Therapeutic Approaches to the Microbiota 31:36 Challenges in Microbiome Drug Development 34:22 The Gut-Brain Connection and Mental Health 39:13 Transitioning from Academia to Pharma 41:45 Insights into Drug Development and Success Stories 44:55 The Long Journey of Drug Development 52:01 The Role of AI in FDA Reviews 55:04 Quick Fire Round: Future of Microbiome Research You must not rely on the information in this video as an alternative to medical advice from your doctor or other professional healthcare provider. If you have any specific questions about any medical matter you should consult your doctor or other professional healthcare provider. If you think you may be suffering from any medical condition you should seek immediate medical attention. You should never delay seeking medical advice, disregard medical advice, or discontinue medical treatment because of the information in this video.

In this episode, Dr James McIlroy chats with Dr Tanya Mongan, clinical associate professor and gastroenterology consultant at the University of Nottingham. Dr Mongan specialises in gut health, particularly the gut–brain connection and faecal microbiota transplantation (FMT). She talks us through the current state of FMT, why it works so well, and how it’s becoming an increasingly important treatment for conditions like inflammatory bowel disease. We also explore her cutting-edge research into microRNA-based medicines—a new field examining tiny molecules that can help protect the gut and may one day be used to treat conditions linked to an unhealthy microbiome, including cystic fibrosis and neurodegenerative diseases. This episode breaks down the complexities of the microbiome in an easy-to-understand way, covering everything from the limits of current testing to the promise of personalised gut treatments. Dr Mongan also shares insights into exciting new tools such as organ-on-chip models, nano-delivery systems for microRNAs, and even zebrafish models used in gut research. If you want to understand where gut science is heading, what’s real and what’s hype, and how future therapies may become more precise and personalised, this is a must-listen. Chapter Markers 00:00 Introduction to Dr Tanya Mongan and gut health 01:51 Has the microbiome “bubble” burst? 03:45 The big challenges in microbiome science 06:13 What the future of microbiome testing could look like 12:45 Understanding faecal microbiota transplantation (FMT) 19:22 How FMT works and what current research shows 26:29 Why the microbiome is so complex 34:57 MicroRNAs: a new frontier in gut health 37:41 Where microRNAs come from 38:18 How microRNAs help protect the gut 39:00 Why delivering microRNAs is difficult 39:19 Nano-formulation: new ways to deliver microRNAs 40:37 The advantages of organ-on-chip models 42:02 Personalised “gut avatars” 43:58 Zebrafish and other models used in gut research 49:27 Clinical applications and future directions 53:17 Microbiome therapy and FMT in clinical practice 56:57 The future of microbiome research and treatment 01:01:23 Diet, supplements, and the microbiome 01:04:34 Weight-loss drugs and how they affect the microbiome 01:07:52 Fascinating facts about the microbiome 01:09:24 Final thoughts and wrap-up