What is the gut microbiome?

It's the community of trillions of microbes — mainly bacteria — living in your intestines. Many help digest food, make certain nutrients, and support your immune system.

How do I improve my gut microbiome?

Mainly through a varied, plant-rich diet high in fiber, plus fermented foods, while going easy on ultra-processed foods and unnecessary antibiotics. Variety feeds a diverse microbiome.

Are at-home microbiome tests worth it?

Be cautious. Microbiome science is young, and many home tests and 'fix your microbiome' products aren't backed by strong evidence yet. The proven advice is to eat more plants, variety, and fiber.

Why is microbiome diversity important?

A diverse microbiome has many species doing different jobs, which supports digestion and health. Diversity largely comes from eating a diverse range of plant foods.

The Gut Microbiome, Explained Simply

Your gut is home to trillions of microbes — mostly bacteria, but also fungi and viruses — known together as the gut microbiome. Far from being unwelcome guests, many of these microbes help you digest food, make certain vitamins, and support your immune system. Looking after them is a big part of gut health.

Quick answer: The gut microbiome is the community of microbes living in your intestines. A diverse, fiber-fed microbiome supports digestion and overall health. You nurture it mainly through a varied, plant-rich diet — not through expensive products.

What the microbiome does

Helps digestion — gut bacteria break down fibers your body can't, releasing useful compounds.
Produces nutrients — some microbes make vitamins and short-chain fatty acids that nourish the gut lining.
Supports immunity — a large part of your immune system lives in and around the gut.
Interacts with the rest of the body — research continues into links between the gut and many aspects of health.

Why diversity matters

A healthy microbiome is generally a diverse one — many different species doing different jobs. Diversity tends to come from a diverse diet: the more varied the plants you eat, the more types of bacteria you feed. A narrow, heavily processed diet does the opposite.

How to support your microbiome

Eat a wide range of plants — aim for variety across fruits, vegetables, whole grains, legumes, nuts, and seeds.
Prioritize fiber — it's the main food for beneficial bacteria (see high-fiber foods).
Include fermented foods — yogurt, kefir, and similar foods add live cultures.
Go easy on ultra-processed foods and unnecessary antibiotics (only take antibiotics when prescribed).

A note on hype

Microbiome science is exciting but young. Be skeptical of products and tests that promise to "fix" your microbiome or diagnose problems from a stool sample at home — the evidence often isn't there yet. The well-established advice is unglamorous: eat more plants, more variety, more fiber.

Track your gut with PoopID

Your stool is a window into your gut. PoopID records your Bristol type, color, and frequency from a photo, helping you see how diet changes affect your digestion over time. See the diet and gut health guide for more.

Sources:
NIDDK — Your Digestive System. niddk.nih.gov
NHS — Digestive health. nhs.uk

This article is for general information only and is not medical advice. Consult a qualified healthcare professional about any symptom that concerns you.