Digestive Detail
Digestive Guide

Gut Microbiome Guide

A plain-English introduction to the communities of microorganisms in the gastrointestinal tract and why microbiome claims require specificity.

Editorially reviewed • Updated September 8, 2026

What the microbiome is

The gastrointestinal tract contains diverse microbial communities. Composition and function vary across people and over time.

Be skeptical of universal claims

“Balances the microbiome” can sound precise while leaving the actual organism, outcome and evidence undefined.

Related: probiotics and prebiotics vs probiotics.

Health note: This page is educational and is not a diagnosis or treatment recommendation. Supplements can cause side effects and interact with medicines. Discuss personal decisions with a qualified healthcare professional.