Although diversity of the gut microbiota in patients with irritable bowel syndrome was similar to controls, a systematic review published in Gastroenterology identified specific bacteria that were either present or protective in IBS.
Paul Moayyedi, PhD, MPH, AGAF, of the division of gastroenterology at McMaster University in Canada, and colleagues wrote that research over the last 10 years has positioned an altered gut microbiota as a possible cause of IBS.
“The previous observational studies have demonstrated that the change of intestinal microbiota as a result of acute gastroenteritis is associated with an increased risk of subsequent development of IBS,” they wrote. “However, the data on specific bacterial groups in IBS is conflicting and still inconclusive.”
Researchers searched databases for case-control studies that compared the fecal or colon microbiomes of adult or pediatric patients with IBS with microbiomes of healthy individuals. They were looking for specific differences in gut microbes between the groups of patients.
In their analysis of 24 studies, investigators identified several harmful bacteria that were increased in patients with IBS, including family Enterobacteriaceae, family Lactobacillaceae, and genus Bacteroides. The presence of these different kinds of bacteria could be due to a number of factors, including previous infection and inflammation.
Moayyedi and colleagues wrote that their most consistent findings were groups of protective bacteria like Clostridiales I, Facalibacterium and genus Bifiobacterium were decreased in patients with IBS compared with controls.
The built-in limitations of the studies included in the review led to a lack of consistency in the results. Moayyedi and colleagues wrote that future studies should describe variables such as antibiotic use and diet and use standardized practice for sample storage and DNA extraction.
“This review highlights the heterogeneity of the microbiota in IBS patients; however, proposes some evidence that certain bacteria may be helpful in IBS treatment,” they concluded. – by Alex Young
Disclosures: The authors report no relevant financial disclosures.