Supplementing Dietary Fibers With a Low FODMAP Diet in Irritable Bowel Syndrome: A Randomized Controlled Crossover Trial

Daniel So; Chu K Yao; Zaid S Ardalan; Phoebe A Thwaites; Kourosh Kalantar-Zadeh; Peter R Gibson; Jane G Muir

doi:10.1016/j.cgh.2021.12.016

Supplementing Dietary Fibers With a Low FODMAP Diet in Irritable Bowel Syndrome: A Randomized Controlled Crossover Trial

Clin Gastroenterol Hepatol. 2022 Sep;20(9):2112-2120.e7. doi: 10.1016/j.cgh.2021.12.016. Epub 2021 Dec 18.

Authors

Daniel So¹, Chu K Yao², Zaid S Ardalan², Phoebe A Thwaites², Kourosh Kalantar-Zadeh³, Peter R Gibson², Jane G Muir²

Affiliations

¹ Department of Gastroenterology, Central Clinical School, Monash University and Alfred Health, Melbourne, Victoria, Australia. Electronic address: daniel.so@monash.edu.
² Department of Gastroenterology, Central Clinical School, Monash University and Alfred Health, Melbourne, Victoria, Australia.
³ Chemical Engineering (Food Science and Technology), University of New South Wales, Sydney, New South Wales, Australia.

PMID: 34929392
DOI: 10.1016/j.cgh.2021.12.016

Abstract

Background & aims: Institution of a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) in patients with irritable bowel syndrome (IBS) may lead to inadequate fiber intake. This trial aimed to investigate the effects of supplementing specific fibers concomitantly with a low FODMAP diet on relevant clinical and physiological indices in symptomatic patients with IBS.

Methods: A double-blind crossover trial was conducted in which 26 patients with IBS were randomly assigned to 1 of 3 low FODMAP diets differing only in total fiber content: control, 23 g/d; sugarcane bagasse, 33 g/d; or fiber combination (sugarcane bagasse with resistant starch), 45 g/d. Each diet lasted 14 days with most food provided and ≥21 days' washout between. Endpoints were assessed during baseline and dietary interventions.

Results: From a median IBS Severity Scoring System total score at baseline of 305, all diets reduced median scores by >50 with no differences in rates of symptom response between the diets: control (57%), sugarcane bagasse (67%), fiber combination (48%) (P = .459). Stool output was ∼50% higher during the fiber-supplemented vs control diets (P < .001 for both). While there were no overall differences overall in stool characteristics, descriptors, and water content, or in gastrointestinal transit times, supplementation with sugarcane bagasse normalized both low stool water content and slow colonic transit from during the control diet.

Conclusions: Concomitant supplementation of fibers during initiation of a low FODMAP diet did not alter symptomatic response in patients with IBS but augmented stool bulk and normalized low stool water content and slow transit. Resistant starch did not exert additional symptomatic benefits over sugarcane bagasse alone. (Australia and New Zealand Clinical Trial Registry; Number, ACTRN12619000691145).

Keywords: Dietary Fiber; Irritable Bowel Syndrome; Low FODMAP Diet; Resistant Starch.

Publication types

Randomized Controlled Trial
Research Support, Non-U.S. Gov't

MeSH terms

Cellulose
Cross-Over Studies
Diet
Diet, Carbohydrate-Restricted
Dietary Fiber
Fermentation
Humans
Irritable Bowel Syndrome*
Resistant Starch
Saccharum*
Water

Substances

Dietary Fiber
Resistant Starch
Water
Cellulose

Associated data

ANZCTR/ACTRN12619000691145