Gut health: Why the microbiome is the key to your wellbeing

Dr. Charalampos Romanos · April 14, 2026 · 6 min read

The gut is not just responsible for digestion. The gut is a complex ecosystem of microorganisms — the microbiome — that directly influences immunity, mood, weight, and even longevity. In my Zurich practice, I view gut health as a foundation of all medicine.

The microbiome — 38 trillion microorganisms

Your gut contains roughly as many bacteria as you have cells. These microorganisms produce vitamins, regulate the immune system, and influence hormone metabolism. A diverse gut flora is essential. The problem is: modern diet, antibiotics, stress — all of this destroys this diversity.

Leaky gut — increased intestinal permeability and the consequences

A damaged gut barrier allows toxins and undigested food particles to enter the bloodstream. This chronically activates the immune system. The body develops allergies, autoimmune reactions, inflammation. This is not just a gastrointestinal problem — it affects the whole body. I see patients with eczema, headaches, even joint pain who simply have a leaky gut problem.

Diagnostics: The stool test that really tells you something

A standard stool test is often too simple. I order a functional stool test that measures gut barrier integrity (zonulin), shows inflammation markers (calprotectin), and analyses microbiome composition. This gives me a picture of what exactly isn't working. Then I can treat specifically.

FODMAP and elimination diets — when they make sense

Low FODMAP diet helps many patients with irritable bowel syndrome. But it's not a permanent state — it's a temporary diagnostic tool. We eliminate for 4-6 weeks, identify triggers, and then slowly reintroduce. The goal is not to avoid everything for life — the goal is to heal the gut.

Probiotics, prebiotics, and postbiotics — the real arsenal

Not all probiotics are the same. I prescribe specifically based on the stool test result. Prebiotics (fibre for good bacteria) are often more important than probiotics. And postbiotics — the end products of good bacteria — have their own therapeutic values. This is functional medicine at its finest.

The gut-brain axis and mental health

Depression, anxiety, even ADHD can stem from gut problems. This is not pseudoscience — it's established neurogastroenterology. A healthy microbiome produces neurotransmitter precursors. I see patients whose depression disappears when I heal their microbiome. This is revolutionary and should be standard.