Fiber supplementation in irritable bowel syndrome: a systematic review and meta-analysis of randomized controlled trials.

Authors

Heidi M Staudacher, Valeria Rucco, Sara Mancell, Eirini Dimidi, Kevin Whelan

Published in

Gastroenterology. Aug 14, 2026. Epub Aug 14, 2026.

Abstract

Fiber supplementation is widely used and recommended for irritable bowel syndrome (IBS), however there is no recent evidence synthesis. We aimed to investigate the efficacy of fiber supplements in IBS through a systematic review and meta-analysis of randomized controlled trials.
We searched MEDLINE, Embase, Web of Science, and Cochrane Central Register of Controlled Trials (inception to 9 April 2026). Trials recruiting adults with IBS that investigated fiber supplements compared with a suitable placebo control were included. Dichotomous clinical response data were summarized with a risk ratio and 95% confidence intervals. The review was registered prospectively on PROSPERO (CRD42024600758).
The search identified 4008 records, and 30 RCTs were eligible including 1904 people with IBS. The most common fiber types were wheat bran (n=7), psyllium (n=6), inulin-type fructans (n=5), and β-galacto-oligosaccharides (B-GOS) (n=2) and two RCTs used fiber co-administration. Sixteen RCTs (n=1293) reported clinical response, with 52% responding to fiber vs 44% to control (RR 1.21 [CI 1.03 to 1.41]; P=0.02; I²=38%), with benefit specifically for psyllium (RR 1.53 [95% CI 1.06 to 2.19]). Nine RCTs (n=497) reported overall GI symptoms (integrative scores), showing no significant effect (SMD -0.25 [95% CI -0.67 to 0.17]; P=0.25; I² =78%), except for B-GOS, which improved symptoms. Subgroup analysis for IBS subtype was not possible for most outcomes.
Fiber supplementation, and specifically psyllium, leads to clinical response in IBS. Future RCTs should report outcomes for individual IBS subtypes or only recruit specific IBS-subtypes to better enable identification of distinct patterns of response.

PMID:
42600900
Bibliographic data and abstract were imported from PubMed on 15 Aug 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.