Different fibres feed different microbes and affect stool, fermentation and symptoms differently.

Gut Health & Microbiome - Microbiome basics

Fibre and prebiotics

Last reviewed 3 August 2026. How we write this.

Different fibres feed different microbes and affect stool, fermentation and symptoms differently.

Whole grains, legumes, fruit, vegetables, nuts and seeds provide varied fibres. Prebiotics are selected substrates used by microorganisms.

Increase intelligently

Build intake gradually.
Drink appropriately.
Use food variety rather than one powder where possible.
Adjust with clinical guidance for strictures or severe gastrointestinal disease.

More fibre can worsen symptoms in some conditions, so tolerance and diagnosis matter.

Educational content only. This does not diagnose a condition or replace assessment and advice from a qualified healthcare professional.

Related in this classroom

The gut microbiome, explained (9 min read)
The gut-brain axis without the hype (9 min read)
IBS: symptoms, diagnosis and treatment (10 min read)

Sources for this classroom

Educational content only. Not medical advice, diagnosis or treatment. Always consult a qualified healthcare professional before changing your health regimen.