Alteration of intestinal microflora is associated with reduction in abdominal bloating and pain in patients with irritable bowel syndrome

OBJECTIVE: The influence of the gastrointestinal (GI) microflora in patient s with irritable bowel syndrome (IBS) has not been clearly elucidated. This study was undertaken to see if patients with IBS have an imbalance in thei r normal colonic flora, as some bacterial taxa are more prone to gas produc tion than others. We also wanted to study whether the flora could be altere d by exogenous supplementation. In a previous study we have characterized t he mucosa-associated lactobacilli in healthy individuals and found some str ains with good colonizing ability. Upon colonization, they seemed to reduce gas formation. METHODS: The study comprised 60 patients with IBS and a normal colonoscopy or barium enema. Patients fulfilling the Rome criteria, without a history o f malabsorption, and with normal blood tests underwent a sigmoidoscopy with biopsy. They were randomized into two groups, one receiving 400 mi per day of a rose-hip drink containing 5 x 10(7) cfu/ml of Lactobacillus plantarum (DSM 9843) and 0.009 g/ml oat flour, and the other group receiving a plain rose-hip drink, comparable in color, texture, and taste. The administratio n lasted for 4 wk. The patients recorded their own GI function, starting 2 wk before the study and continuing throughout the study period. Twelve mont hs after the end of the study all patients were asked to complete the same questionnaire regarding their symptomatology as at the start of the study. RESULTS: All patients tolerated the products well. The patients receiving L b, plantarum had these bacteria on rectal biopsies. There were no major cha nges of Enterobacteriaceae in either group, before or after the study, but the Enterococci increased in the placebo group and remained unchanged in th e test group. Flatulence was rapidly and significantly reduced in the test group compared with the placebo group (number of days with abundant gas pro duction, test group 6.5 before, 3.1 after Its 7.4 before and 5.6 after for the placebo group). Abdominal pain was reduced in both groups. At the 12-mo nth follow-up, patients in the test group maintained a better overall GI fu nction than control patients. Then was no difference between the groups reg arding bloating. Fifty-nine percent of the test group patients had a contin uous intake of fermented products, whereas the corresponding figure for the control patients was 73%. CONCLUSIONS: The results of the study indicate that the administration of L b. plantarum With known probiotic properties decreased pain and flatulence in patients with IBS. The fiber content of the test solution was minimal an d it is unlikely that the fiber content could have had any effect. This typ e of probiotic therapy warrants further studies in IBS patients. (C) 2000 b y Am. Cell. of Gastroenterology.