Gut Microbiota-Derived Metabolites in Irritable Bowel Syndrome.

Lin Xiao,Lishou Xiong,Qin Liu,Mei Luo

doi:10.3389/fcimb.2021.729346

Abstract

Irritable bowel syndrome (IBS) is the most common functional bowel disorder worldwide and is associated with visceral hypersensitivity, gut motility, immunomodulation, gut microbiota alterations, and dysfunction of the brain-gut axis; however, its pathophysiology remains poorly understood. Gut microbiota and its metabolites are proposed as possible etiological factors of IBS. The aim of our study was to investigate specific types of microbiota-derived metabolites, especially bile acids, short-chain fatty acids, vitamins, amino acids, serotonin and hypoxanthine, which are all implicated in the pathogenesis of IBS. Metabolites-focused research has identified multiple microbial targets relevant to IBS patients, important roles of microbiota-derived metabolites in the development of IBS symptoms have been established. Thus, we provide an overview of gut microbiota and their metabolites on the different subtypes of IBS (constipation-predominant IBS-C, diarrhea-predominant IBS-D) and present controversial views regarding the role of microbiota in IBS.

Highlights

Irritable bowel syndrome (IBS) is a common gastrointestinal bowel disorder, characterized by recurrent abdominal pain and discomfort or alterations in bowel habits
Understanding variations and fluctuations in the concentrations of host or microbiotaderived metabolites that can be used to infer processes contributing to the symptoms and severity of IBS will provide important new insights for functional gastrointestinal disorders (FGDs) research
We found that the abundance of microorganisms and their corresponding metabolites in IBS-C and IBS-D differ, thereby providing a new avenue for the diagnosis and treatment of different IBS subtypes in the future

Summary

Introduction

Irritable bowel syndrome (IBS) is a common gastrointestinal bowel disorder, characterized by recurrent abdominal pain and discomfort or alterations in bowel habits. Women are more susceptible (1.67 times) than men (Study Group of Functional Gastrointestinal Disorders et al, 2020) to suffer from IBS. Based on different geographical regions and diagnostic criteria, the global prevalence of IBS is approximately 10–15% and is 1.4–11.5% in China. The proportion of IBS patients seeking clinical service in clinics is below 25% in China (Study Group of Functional Gastrointestinal Disorders et al, 2020). The pathogenesis of IBS is associated with disordered gastrointestinal motility, abnormal intestinal secretion, visceral hypersensitivity, altered gut-brain axis, and intestinal permeability, all of which can be affected by the gut microbial community (Jeffery et al, 2020). Owing to the heterogeneous characterization, IBS poses a significant medical burden, and considerably impact patient quality of life of patients with IBS (Enck et al, 2016; Sperber et al, 2017)

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