A role for the gut microbiota in IBS

• Published in: Nature reviews. Gastroenterology & hepatology Vol. 11; no. 8; pp. 497 - 505
• Main Author: Collins, Stephen M.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.08.2014; Nature Publishing Group
• Subjects: 49/40; 49/47; 64/60; 692/698/2741/2135; 692/699/1503/2753/2071; Animals; Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - therapeutic use; Behavior - physiology; Biomedicine; Brain - physiology; Colon - microbiology; Development and progression; Dietary Carbohydrates - pharmacology; Dietary Fats - pharmacology; Fermentation; Gastroenterology; Health aspects; Hepatology; Host-bacteria relationships; Humans; Infection - microbiology; Intestine, Small - microbiology; Intestines - microbiology; Irritable bowel syndrome; Irritable Bowel Syndrome - immunology; Irritable Bowel Syndrome - microbiology; Irritable Bowel Syndrome - physiopathology; Irritable Bowel Syndrome - therapy; Medicine & Public Health; Microbiota (Symbiotic organisms); Physiological research; Prebiotics; Probiotics - therapeutic use; review-article; Stress, Psychological - microbiology
• ISSN: 1759-5045; 1759-5053; 1759-5053
• DOI: 10.1038/nrgastro.2014.40

Key Points Animal studies have demonstrated that changes in the gut microbiota result in altered host function, in domains relevant to IBS (gut motility, visceral pain responses, intestinal permeability, and brain function and behaviour) Gut microbiota composition is altered in at least a subset of patients with IBS (most commonly diarrhoea-predominant IBS), but no microbial 'signature' that could act as an IBS biomarker has been identified Considerable interest exists in the ability of bacteria to produce substances that interact with the host to influence gut and brain function, which include fatty acids, tryptophan and neurotransmitters Dysbiosis in IBS is characterized by a loss of microbial diversity and temporal instability; contributing factors include diet, stress, infection, antibiotic usage, immune activation and low-grade inflammation The gut microbiota from patients with IBS, but not healthy individuals, can induce gut dysfunction in mice reminiscent of that seen in IBS, strongly suggesting that the microbiota contributes to the expression of IBS Emerging evidence supports the efficacy of select and limited microbiota-directed therapies in treating IBS, and to date these include prebiotics, probiotics and selected antibiotics The gut microbiota is now acknowledged to have a profound effect on human health and disease. Here, Stephen Collins explores the role of the gut microbiota in the development of IBS, describing experimental evidence and clinical observational and trial data that implicates the gut microbiota in the manifestation of IBS. The past decade has witnessed an explosion of knowledge regarding the vast microbial community that resides within our intestine—the gut microbiota. The topic has generated great expectations in terms of gaining a better understanding of disorders ranging from IBD to metabolic disorders and obesity. IBS is a condition for which investigators have long been in search of plausible underlying pathogeneses and it is inevitable that altered composition or function of the gut microbiota will be considered as a potential aetiological factor in at least a subset of patients with IBS. This Review describes the evidence implicating the gut microbiota in not only the expression of the intestinal manifestations of IBS, but also the psychiatric morbidity that coexists in up to 80% of patients with IBS. The evidence described herein ranges from proof-of-concept studies in animals to observational studies and clinical trials in humans. The gut microbiota is subject to influences from a diverse range of factors including diet, antibiotic usage, infection and stress. These factors have previously been implicated in the pathophysiology of IBS and further prompt consideration of a role for the gut microbiota in IBS.