Plain language summary
Irritable bowel syndrome (IBS) is a chronic functional bowel disorder that is characterised by recurring abdominal pain over ≥3 months within a 6-month period in association with altered bowel habits. Symptomatic treatment of IBS includes dietary adaptation, with a focus on prebiotics, probiotics, gluten, and fermentable oligo-, di-, monosaccharides and polyols (FODMAPs). The main aim of this study was to investigate the effects of weeklong interventions with high intakes of a wide range of FODMAPs, gluten, or a nonfermentable placebo in subjects with moderate to severe IBS. This study is a double-blind, placebo-controlled, randomised 3-way study with triple crossover design. One-hundred and ten participants were enrolled and randomly assigned for the study. Results show that a mixture of widely consumed FODMAPs caused only modest worsening of gastrointestinal symptoms compared with gluten and placebo. Authors conclude that there were interindividual variability in the intervention responses. Thus, future studies should investigate these differences to understand possible underlying disease mechanisms.
Abstract
BACKGROUND Irritable bowel syndrome (IBS) has been associated with diets rich in fermentable oligo-, di-, monosaccharides, and polyols (FODMAPs), and gluten. Most previous studies have been single-blind and have focused on the elimination of FODMAPs or provocation with single FODMAPs. The effect of gluten is unclear, large trials isolating the effect of gluten from that of FODMAPs are needed. OBJECTIVES The aims of this study were to ensure high intakes of a wide range of FODMAPs, gluten, or placebo, and to evaluate the effects on IBS symptoms using the IBS-severity scoring system (IBS-SSS). METHODS The study was carried out with a double-blind, placebo-controlled, randomized 3-way crossover design in a clinical facility in Uppsala from September 2018 to June 2019. In all, 110 participants fulfilling the IBS Rome IV criteria, with moderate to severe IBS, were randomly assigned; 103 (90 female, 13 male) completed the trial. Throughout, IBS participants maintained a diet with minimal FODMAP content and no gluten. Participants were block-randomly assigned to 1-wk interventions with FODMAPs (50 g/d), gluten (17.3 g/d), or placebo, separated by 1-wk washout. All participants who completed ≥1 intervention were included in the intention-to-treat analysis. RESULTS In participants with IBS (n = 103), FODMAPs caused higher IBS-SSS scores (mean 240 [95% CI: 222, 257]) than placebo (198 [180, 215]; P = 0.00056) or gluten (208 [190, 226]; P = 0.013); no differences were found between the placebo and gluten groups (P = 1.0). There were large interindividual differences in IBS-SSS scores associated with treatment. No adverse events were reported. CONCLUSION In participants with IBS, FODMAPs had a modest effect on typical IBS symptoms, whereas gluten had no effect. The large interindividual differences in responses to the interventions warrant further detailed studies to identify possible underlying causes and enable individual prediction of responses. This trial was registered at www.clinicaltrials.gov as NCT03653689.
Methodological quality
Jadad score
:
5
Allocation concealment
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Yes
