MECHANISM ENGINE
What Is the Microbiome?
Gut health felt like a vague, faddish phrase to me for years. Then I actually looked into what’s living down there and what it’s doing, and it stopped feeling vague at all. It’s doing a specific, measurable job, every single day.
The Lush Garden vs the Cracked Council Flowerbed
A diverse, well-fed microbiome looks like a proper cottage garden, dozens of different species, all doing slightly different jobs, resilient because there’s so much variety that no single setback wipes the whole thing out. A depleted microbiome, low variety, fed mostly on the same few processed staples, looks more like a cracked council flowerbed, a handful of tough, opportunistic species surviving in poor soil, nothing thriving. Same patch of ground, same potential. What actually grows there depends almost entirely on what you feed it.
The gut microbiome is the community of trillions of bacteria and other microbes living mainly in the large intestine. It ferments fibre into short-chain fatty acids that feed gut cells and influence inflammation, produces certain vitamins, and communicates with the brain via the vagus nerve and other pathways. Diversity generally increases with a wide range of plant fibres and fermented foods, and decreases with low-fibre, highly processed diets and frequent antibiotic use.
NHS dietary guidance recommends fibre intake of 30g a day, which research links to greater microbiome diversity; NICE materials note emerging but still developing evidence connecting gut bacteria diversity to metabolic and immune health.
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Related mechanisms
Educational only, not medical advice. Speak to your GP before changing your fasting pattern, diet, or medication.
What this is based on
NHS and NICE guidance, cross-referenced against Neil’s own NHS blood test record going back to April 2012. See the full timeline and current numbers.