In recent years, gut health has become a rising topic across Asia. From common fermented foods and probiotics to discussions about stress, immunity, and even mental health.
But with so much information online, it’s easy to feel confused:
- Does gut health really affect the brain?
- Are probiotics essential — or just another wellness trend?
- And how much does diet actually matter?
To help cut through the noise, we turn to insights shared by Jack Gilbert, a leading microbiome scientist, who has spent decades studying how the gut microbiome influences human health across the lifespan.
Besides, the interview also features Dr.Tsai Ying-chieh, the founding father of one of the top three psychobiotic research centers, who hosted the discussion and presented questions submitted by Bened Life customers.
What Is the Gut Microbiome - and Why Does It Matter?
Fact: There are trillions of Microbes Live Inside the Human Body
The human gut is home to trillions of microorganisms, including bacteria, viruses, and fungi, collectively known as the gut microbiome. They’re long-term partners that help the body function properly.
As Dr. Gilbert often explains, humans do not just comprise human cells, we are basically an ecosystem. Our microbes help us adapt to our environment, process food, and interact with the world around us.
What the Gut Microbiome Actually Does:
While digestion is the most familiar role, the gut microbiome is also deeply involved in:
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Supporting immune system development
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Regulating inflammation
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Influencing metabolism and energy balance
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Communicating with the nervous system
Common Myths About the Gut Microbiome (And What Science Says)
Myth #1: “Gut Health Only Matters To Digestion”
One of the biggest misconceptions is that the gut only matters when you have stomach problems.
In reality, the gut and brain are in constant communication through what scientists call the gut–brain axis. This two-way system connects the digestive tract with the nervous system, immune responses, and hormone signaling.
Gut bacteria are linked to various health conditions, including metabolic disease to mental health disorders.
Dr. Gilbert has pointed out that stress can disturb the gut — and an imbalanced gut can, in turn, influence how the body responds to stress. This explains why emotional tension can sometimes lead to digestive issues like diarrhea or constipation.
Myth #2: “Stay away from bacteria! They Are Bad”
Not all bacteria are harmful. In fact, many are essential.
A healthy microbiome is about balance, not elimination. Problems arise when certain bacteria dominate due to factors like excessive sugar intake, lack of dietary variety, or ongoing stress.
Myth #3: “Just Eat Healthy Food, Your Gut Will Be Fine”
Gut health reflects patterns over time, not one-off “clean eating” days. Travel, irregular sleep, high stress, and inconsistent diets can all influence microbial balance - something many Singaporeans experience due to busy urban lifestyles.
How Diet Shapes Your Gut Microbiome Every Day
What You Eat Also Feeds Your Microbes
Food doesn’t just nourish you — it nourishes your microbes too. Different bacteria thrive on different nutrients, particularly:
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Dietary fibre from vegetables, fruits, and whole grains
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Plant diversity
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Adequate protein
Sugar, Ultra-Processed Foods, and the Microbiome
Diets high in added sugar and ultra-processed foods can shift the microbiome toward bacteria associated with inflammation and discomfort.
This may also help explain why people often crave sweet foods when stressed. According to microbiome research, gut bacteria can influence cravings, creating feedback loops between diet, microbes, and behaviour.
Can Short-Term Diet Changes Make A Significant Difference?
A well-known research study published in Nature Communications found that short-term diet changes, as little as two weeks, have been shown in tightly controlled studies to rapidly shift the gut microbiome and reduce biomarkers linked to colorectal cancer risk, such as colon inflammation, harmful bile acid patterns, and low butyrate production.
Why Stress, Travel, and Emotions Can Upset Your Gut
The Two-Way Conversation Between the Gut and the Brain
Stress activates the nervous system, which can change gut motility and sensitivity. This is why some people experience digestive upset during stressful periods or while travelling.
Dr. Gilbert has emphasised that what happens in the gut does not stay in the gut — it can affect how the body feels and functions more broadly.
What Are Probiotics - and What Do They Actually Do?
What Probiotics Are
According to the World Health Organization, probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.
However, not all probiotics do the same thing. The benefit depends on the exact strain, dose, and use, not just the species name.
Why Clinical Studies Matter
A probiotic that has been clinically studied is more likely to:
- Make specific, realistic claims
- Avoid exaggerated “cure-all” language
- Be transparent about what it can and cannot do
While many products use the word “probiotic,” only human clinical trials can confirm which specific strain works, what it supports, the right dosage, and who it’s suitable for.
Studies help ensure a probiotic’s benefits are clear, realistic, and safe, giving consumers confidence that they’re choosing something backed by science, not just marketing.
What Probiotics Do Not Do
A common misunderstanding is that probiotics permanently “take over” your gut. Most probiotics do not colonise long-term.
As Dr. Gilbert explains, probiotics mainly interact with the immune system and gut environment as they pass through, helping to regulate processes rather than replacing existing microbes.
Can Probiotics Affect Mental Health and the Brain?
Introducing the Gut–Brain Axis
The gut communicates with the brain through nerves, immune signals, and metabolic by-products — without probiotics needing to cross the blood–brain barrier.
What Are Psychobiotics?
Psychobiotics are specific probiotic strains studied for their ability to support mental and emotional well-being through the gut–brain axis. They represent a growing area of microbiome science focused on mood, stress, and neurological balance.
Dr. Gilbert has noted that naming aside, what matters is evidence — if a strain is supported by solid preclinical and clinical research, it moves beyond hype.
Why Gut Health Becomes More Important as We Age
As we get older, changes in the gut happen naturally. One of the biggest shifts is that the gut microbiome becomes less diverse, meaning there are fewer types of helpful bacteria working together in the digestive system.
When this diversity drops, the gut can become more sensitive to everyday stress, illness, medications, or changes in diet - all of which tend to happen more often with age.
Digestion can also slow down over time. Food may move through the gut more slowly, which is why bloating or constipation becomes more common in older adults.
Aging also affects the immune system and how the body manages inflammation, both of which are closely linked to gut health.
Popular Diet Patterns Studied in Older Adults & Parkinson’s
Beyond individual nutrients, researchers increasingly focus on overall eating patterns rather than single “superfoods.” One of the most studied patterns for older adults, including those with Parkinson’s, is Mediterranean-style eating.
This approach emphasises vegetables, fruits, whole grains, beans, nuts, fish, and healthy fats like olive oil, while keeping highly processed foods and excess saturated fats to a minimum.
Why Supporting Gut Health Early Matters
For some seniors, constipation is not just a digestive inconvenience but an early non-movement sign of Parkinson’s. Research suggests it can appear years before more familiar symptoms like tremors or stiffness. This may be linked to changes in gut–brain communication, where signals between the digestive system and nervous system become disrupted, affecting bowel regularity early on.
Because of this, gut support matters early, not late. Noticing and addressing ongoing constipation can help support comfort and gut balance sooner, reinforcing gut health as an important part of overall well-being and healthy aging.
What Most People Get Wrong About Gut Health
It’s Not About Perfection
Gut health does not require extreme diets or constant restriction.
It’s About Consistent, Supportive Habits
Small, realistic changes — improving dietary variety, managing stress, staying active, and using evidence-based support where appropriate — are often more sustainable and effective.
Key Takeaways: Supporting Your Gut Microbiome, Step by Step
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Focus on dietary variety, especially plant foods
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Reduce excess sugar and ultra-processed foods
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Recognise stress as a gut health factor
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Choose probiotics based on scientific evidence, not marketing claims
Watch the full interview with Dr. Jack Gilbert here:
