Inside Matters

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

Revolutionising Liver Health: The Link Between Gut Health, Genetics, and Lifestyle

In this episode, we dive deep into the intricate connections between liver health, gut health, genetic predispositions, and lifestyle factors. Our guest, Gary, a seasoned physician and entrepreneur, shares his extensive experience from pioneering liver disease research in the 90s to running a successful metabolic clinic focused on functional medicine today. Learn about the evolution of understanding fatty liver diseases like NASH and MASH, the impact of processed foods, and the groundbreaking treatments emerging, including the promising effects of GLP-1 therapies. Gary also discusses the pivotal role of a clean diet, exercise, and quality sleep in managing liver health, and the challenges of implementing these changes in a clinical setting. Don't miss this insightful conversation packed with practical advice and forward-thinking approaches to improving liver and overall metabolic health.

00:00 The State of Food Quality in America vs Scotland
02:39 Understanding Fatty Liver Disease: Past and Present
05:29 Genetic and Environmental Factors in Fatty Liver Disease
08:13 The Evolution of MASH: From NASH to Metabolic Health
10:46 Emerging Treatments and Medications for Liver Disease
13:35 The Role of GLP-1s in Managing Liver Health
16:18 The Gut–Liver Connection: A Historical Perspective
19:07 Building a Successful Liver Clinic: Insights and Challenges
33:52 Understanding Metabolic Health and Genetic Testing
35:13 The Importance of Gut Health
37:39 Transforming Workplace Wellness Initiatives
45:48 The Future of Functional Medicine
51:30 Addressing Liver Health and Alcohol Consumption

Takeaways

The quality of food in America is declining, impacting health.

Fatty liver disease is increasingly common, especially among those with higher body mass indexes.

Genetic predisposition plays a significant role in liver disease.

MASH is a critical condition that combines fatty liver with inflammation.

Advancements in GLP-1 medications show promise for treating liver disease.

Gut health is essential for overall wellness and liver health.

Guy Neff's journey reflects a blend of medicine and business acumen.

Building a successful liver clinic requires navigating numerous challenges.

Functional medicine is gaining traction as a holistic approach to health.

Routine testing for liver health is crucial for early detection and intervention.

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 podcast.