Diverse Nutrition and the Gut Microbiome – The Invisible Foundation of Health
- Katrin Peo
- 47 minutes ago
- 5 min read
Why the Food We Eat Shapes Far More Than Digestion
When we think about digestion, we often imagine the stomach breaking food down into smaller pieces. In reality, digestion is a highly complex, multi‑stage process involving enzymes, hormones, transporters, organs – and trillions of microorganisms living inside our gut. Only when this system works well can the food we eat be transformed into usable building blocks: energy, structural components for cells, signalling molecules, and compounds that support immunity, brain health and metabolism.
This article is the third part of my mini‑series on the human body and nutrition. In the previous posts, I explored:
Here, we take the next step and focus on the gut microbiome – still an often overlooked but very essential part of human health.
What Is the Gut Microbiome?
The gut microbiome refers to the community of microorganisms – mainly bacteria, but also viruses, fungi and archaea – that live primarily in the large intestine. Each person hosts a unique microbial ecosystem, shaped by genetics, early life exposure, diet, lifestyle, medication use and environment. Your microbiome is as unique to you as your fingerprint.
A healthy gut microbiome is not defined by one “perfect” bacterial strain, but by diversity, balance and functionality. The microbes in the gut help us digest food components we otherwise could not process, especially dietary fibres and resistant starches.
Why Microbial Diversity Matters
Microbial diversity in the gut is strongly associated with better overall health. A diverse microbiome is more resilient, adaptable and capable of performing a wide range of functions, including:
breaking down complex carbohydrates and fibres
producing short‑chain fatty acids (SCFAs) such as butyrate, acetate and propionate
supporting gut barrier integrity
training and regulating the immune system
influencing inflammation levels in the body
interacting with hormones and neurotransmitters via the gut–brain axis
Low microbial diversity has been linked to digestive disorders, metabolic issues, chronic inflammation, allergies and autoimmune conditions (such as rheumatoid arthritis, lupus, multiple sclerosis etc).
The Gut Microbiome and the Immune System
Around 70% of the immune system is located in and around the gut. The microbiome plays a key role in educating immune cells to distinguish between harmless substances (like food proteins) and real threats (such as pathogens).
When the gut ecosystem is imbalanced, immune regulation may suffer. This can contribute to increased susceptibility to infections, food sensitivities, allergies and inflammatory conditions.
Gut Microbiome and Heart Health
The gut microbiome plays an important role in cardiovascular health. Certain gut bacteria help regulate cholesterol metabolism, influence blood pressure and reduce chronic low-grade inflammation – all key factors in heart disease risk. An imbalanced microbiome may produce metabolites such as TMAO (trimethylamine N-oxide), which has been linked to a higher risk of atherosclerosis, while a diverse, fibre-rich microbiome supports the production of short-chain fatty acids that help protect blood vessels and support healthy lipid metabolism.
Gut Microbiome and Brain Health
The gut and brain are in constant two-way communication through the gut–brain axis. Gut microbes influence brain health by producing neurotransmitter precursors, regulating inflammation, and interacting with the nervous and immune systems. A healthy and diverse microbiome is associated with better mood regulation, stress resilience and cognitive function, while imbalances in gut bacteria have been linked to anxiety, depression, neuro-inflammation and even neurodegenerative conditions, like dementia.
Gut Health, Weight Regulation and Metabolism
Research shows that the gut microbiome influences how efficiently we extract energy from food, how we regulate appetite and how we respond to insulin. Interestingly, studies have found that people with overweight or obesity often harbour a higher abundance of bacterial genes involved in carbohydrate breakdown.
After the digestive enzymes in the stomach and small intestine have done most of their work, the remaining food mass moves into the large intestine. Here, gut bacteria use leftover carbohydrates, proteins and fats as substrates for their own metabolism. During this process, they produce various compounds that can pass through the intestinal wall and enter the human bloodstream.
Many of these bacterial metabolites are similar to those produced during human carbohydrate digestion. In practical terms, this means that certain gut bacteria are able to extract additional energy from carbohydrates that the human body itself cannot digest. As a result, the total amount of energy obtained from food may be higher due to bacterial activity. Excessive energy intake and an imbalanced diet are likely to promote the growth of bacterial populations that are more efficient at harvesting energy.
It is important to emphasise that body weight regulation is complex and multifactorial. The gut microbiome does not act in isolation, but it clearly interacts with diet quality, meal composition, physical activity, sleep and stress to influence long-term metabolic health.
Gut microbiome and skin health
Skin health is closely connected to gut health via the gut–skin axis. The gut microbiome influences immune responses, inflammation and nutrient availability, all of which affect the skin. Dysbiosis in the gut has been associated with skin conditions such as acne, eczema, psoriasis and rosacea. Supporting gut microbial balance through diverse, nutrient-rich foods may help reduce systemic inflammation and support clearer, more resilient skin.
Probiotics, Prebiotics and Food First
Probiotics are live microorganisms that may confer health benefits when consumed in adequate amounts. Prebiotics, on the other hand, are fibres and compounds that feed beneficial bacteria already present in the gut.
While probiotic supplements can be useful and needed in specific situations and gut conditions, they are not a substitute for a varied, nutrient‑dense diet. A food‑first approach remains the most reliable way to support microbial diversity.
Key microbiome‑supportive foods include:
vegetables of different colours (think of rainbow of colours in your weekly menu)
berries and fruits (different types, different colour)
legumes (beans, lentils)
whole grains
nuts and seeds
herbs and spices
fermented foods such as kefir, yoghurt, sauerkraut and kimchi
Why Food Quality Matters
Digestion and absorption can only work optimally when the body is given real, nutrient‑dense food. Highly processed products often lack fibre, contain refined carbohydrates, additives and emulsifiers, and provide little support for gut health.
When choosing what to eat, it is worth pausing and asking:
Is this real food that provides my body with essential nutrients and building blocks?
Or is it a highly processed, food‑like product with limited nutritional value?
Small, consistent choices made daily have a profound impact on digestive function, microbial balance and long‑term health.
Final Thoughts
A well‑functioning digestive system is not just about avoiding discomfort. It is a foundation for energy production, immune defence, mental wellbeing and metabolic health. By supporting digestion and nourishing the gut microbiome with diverse, minimally processed foods, we support the body’s ability to thrive.
Understanding how complex and interconnected this system is can help us make more informed, mindful choices – one meal at a time.
If you feel that your current diet needs a review to understand what can be improved, so it's more balanced and supporting gut health, don't hesitate to reach out to me for nutrition counselling at info@katrinpeo.com.
Additional reading from scientific research:
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