Department of Gastroenterology, Central Clinical School, Monash University and Alfred Health, Melbourne, Victoria, Australia.
Food & Mood Centre, Institute for Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, Victoria, Australia.
Am J Clin Nutr. 2022 Oct 6;116(4):943-952. doi: 10.1093/ajcn/nqac176.
A low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet is increasingly used to manage symptoms in irritable bowel syndrome (IBS). Although this approach may alter the colonic microbiome, the nature of these changes has not been comprehensively synthesized.
The aim of this study was to conduct a systematic review with meta-analysis of randomized controlled trials examining the impact of a low FODMAP diet on the composition and function of the microbiome in patients with IBS.
A systematic search was conducted for randomized controlled trials evaluating the effects of a low FODMAP diet on the colonic microbiome in patients with IBS in MEDLINE, EMBASE, CENTRAL, and Web of Science from inception to April 2022. Outcomes included diversity of the microbiome, specific bacterial abundances, fecal SCFA concentration, and fecal pH. For fecal SCFA concentrations and pH, meta-analyses were performed via a random-effects model.
Nine trials involving 403 patients were included. There were no clear effects of the low FODMAP diet on diversity of the microbiome. A low FODMAP diet consistently led to lower abundance of Bifidobacteria, but there were no clear effects on diversity of the microbiome or abundances of other specific taxa. There were no differences in total fecal SCFA concentration between the low FODMAP diet and control diets (standardized mean difference: -0.25; 95% CI: -0.63, 0.13; P = 0.20), nor were there differences for fecal concentrations of specific SCFAs or fecal pH.
In patients with IBS, the effects of a low FODMAP diet on the colonic microbiome appear to be specific to Bifidobacteria with no consistent impacts on other microbiome metrics, including diversity, fecal SCFA concentrations, and fecal pH. Further, adequately powered trials are needed to confirm these findings.This review was registered at https://www.crd.york.ac.uk/prospero/ as CRD42020192243.
低发酵寡糖、双糖、单糖和多元醇（FODMAP）饮食越来越多地用于治疗肠易激综合征（IBS）的症状。虽然这种方法可能会改变结肠微生物组，但这些变化的性质尚未得到全面综合。
本研究旨在对随机对照试验进行系统评价和荟萃分析，以检查低 FODMAP 饮食对 IBS 患者肠道微生物组组成和功能的影响。
从 MEDLINE、EMBASE、CENTRAL 和 Web of Science 数据库系统地检索了评估低 FODMAP 饮食对 IBS 患者结肠微生物组影响的随机对照试验，检索时间从建库至 2022 年 4 月。结果包括微生物组的多样性、特定细菌的丰度、粪便短链脂肪酸（SCFA）浓度和粪便 pH 值。对于粪便 SCFA 浓度和 pH 值，通过随机效应模型进行荟萃分析。
纳入了 9 项涉及 403 名患者的试验。低 FODMAP 饮食对微生物组的多样性没有明显影响。低 FODMAP 饮食一致导致双歧杆菌丰度降低，但对微生物组多样性或其他特定分类群的丰度没有明显影响。低 FODMAP 饮食与对照组饮食之间的粪便总 SCFA 浓度没有差异（标准化均数差：-0.25；95%CI：-0.63，0.13；P=0.20），粪便中特定 SCFA 的浓度或粪便 pH 值也没有差异。
在 IBS 患者中，低 FODMAP 饮食对结肠微生物组的影响似乎仅限于双歧杆菌，对其他微生物组指标（包括多样性、粪便 SCFA 浓度和粪便 pH 值）没有一致影响。此外，需要进行足够大的试验来证实这些发现。本综述在 https://www.crd.york.ac.uk/prospero/ 注册为 CRD42020192243。
