Effect of multispecies probiotics on irritable bowel syndrome: A randomized, double-blind, placebo-controlled trial

摘要

Background and Aim: The efficacy of treatment with multispecies probiotics on irritable bowel syndrome (IBS) symptoms and the alterations of gut microbiota in patients who have taken probiotics were investigated. Methods: This randomized, double-blind, placebo-controlled trial involved 49 IBS patients (probiotics: 25, placebo: 24) diagnosed according to the Rome III criteria. Patients were randomly assigned to two groups: either to receive multispecies probiotics (a mixture of Bifidobacterium longum, B.bifidum, B.lactis, Lactobacillus acidophilus, L.rhamnosus, and Streptococcus thermophilus) twice a day for 4 weeks or to receive a placebo twice a day for 4 weeks. The primary efficacy end-point was the proportion of participants whose IBS symptoms were substantially relieved at week 4. Secondary end-points were the intensity of abdominal pain/discomfort, bloating, stool frequency/consistency, alterations in fecal microflora over the 4 weeks. Fecal microflora were analyzed in 34 patients (probiotics: 17, placebo: 17) by quantitative real-time polymerase chain reaction assays. Results: The proportion of patients whose IBS symptoms were substantially relieved at week 4 was significantly higher in the probiotics group than in the placebo group: 68.0% (17/25) versus 37.5% (9/24) (P<0.05). Secondary end-points such as improvement in abdominal pain/discomfort and bloating occurred in the probiotics group but not in the placebo group. Fecal analysis revealed that B.lactis, L.rhamnosus, and S.thermophilus had increased significantly in the probiotics group after 4 weeks and that B.lactis had increased in the placebo group. Conclusions: Multispecies probiotics are effective in IBS patients and induce the alterations in the composition of intestinal microbiota.