Prebiotics

inulin · fructooligosaccharides · FOS · galactooligosaccharides · GOS

Snapshot

Indications	Contraindications
Bifidobacterium growth^{1, 2} Stool laxation^1–5 Weight management^6–9 Insulin sensitivity¹ Calcium and magnesium absorption¹ Acne vulgaris adjunct¹⁰	Children under 3 years¹¹ Egg allergy in egg-containing products¹¹

Prebiotics are non-digestible carbohydrates, chiefly inulin-type fructans, fructooligosaccharides, and galactooligosaccharides, that colonic bacteria ferment selectively, expanding Bifidobacterium, Lactobacillus, and Faecalibacterium prausnitzii¹. That fermentation drives most supplemental use: stool laxation, glucose and lipid markers, and calcium and magnesium absorption in healthy adults. Weight management follows, and prebiotics are also taken for bone health, mood, and allergy prevention, where trials are mixed.

Chicory inulin-type fructans reduced body weight, fat mass, and waist circumference in a meta-analysis of randomized trials⁶. Bowel uses are weaker: a network meta-analysis found prebiotics and synbiotics did not significantly improve irritable bowel syndrome symptoms in adults¹². In a 2026 randomized trial of older adults with probable sarcopenia, adding a fructooligosaccharide and inulin prebiotic to phenolic-rich olive oil increased ultrasound measures of quadriceps and rectus femoris muscle size; it has not been replicated. The label database lists 881 products listing prebiotics, mostly capsules paired with probiotics; see Form comparison.

Bloating and flatulence reflect fermentation, though a fructooligosaccharide meta-analysis found no difference from comparators in adverse gastrointestinal symptoms. United States product labels warn against use under age 3 because of choking risk¹¹, and some list egg as an allergen¹¹.

Last updated October 16, 2026. Read how we make monographs.

In the full monograph

91 sources, 77 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources