title: Irritable bowel syndrome and small intestinal bacterial overgrowth: meaningful association or unnecessary hype.
abstract: Irritable bowel syndrome (IBS) is a common condition characterized by abdominal pain or discomfort, bloating, and altered stool form and passage. Small intestinal bacterial overgrowth (SIBO) is a condition in which there is overgrowth of bacteria in small bowel in excess of 10⁵ colony forming units per milliliter on culture of the upper gut aspirate. Frequency of SIBO varied from 4%-78% among patients with IBS and from 1%-40% among controls. Higher frequency in some studies might be due to fallacious criteria [post-lactulose breath-hydrogen rise 20 PPM above basal within 90 min (early-peak)]. Glucose hydrogen breath test (GHBT) has a low sensitivity to diagnose SIBO. Hence, studies based on GHBT might have under-estimated frequency of SIBO. Therefore, it is important to analyze these studies carefully to evaluate whether the reported association between IBS and SIBO is over or under-projected. This review evaluates studies on association between SIBO and IBS, discordance between different studies, their strength and weakness including methodological issues and evidence on therapeutic manipulation of gut flora on symptoms of IBS.
authors.affiliation: Uday C Ghoshal, Deepakshi Srivastava, Department of Gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow 226104, India.
authors.forename: Uday C
authors.initials: UC
authors.lastname: Ghoshal
authors.affiliation: Uday C Ghoshal, Deepakshi Srivastava, Department of Gastroenterology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow 226104, India.
authors.forename: Deepakshi
authors.initials: D
authors.lastname: Srivastava
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001419:Bacteria / Q000254:growth & development* / Q000378:metabolism; D001944:Breath Tests; D005285:Fermentation; D006790:Host-Parasite Interactions; D006801:Humans; D007421:Intestine, Small / Q000378:metabolism / Q000382:microbiology*; D043183:Irritable Bowel Syndrome / Q000175:diagnosis / Q000378:metabolism / Q000382:microbiology* / Q000628:therapy; D010641:Phenotype; D011237:Predictive Value of Tests; D019936:Probiotics / Q000627:therapeutic use; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents
keywords: Dysbiosis; Functional bowel disease; Glucose hydrogen breath test; Gut flora; Lactulose hydrogen breath test