Effects of Bifidobacterium longum BB536 and Lactobacillus rhamnosus HN001 in IBS patients

BACKGROUND: Irritable bowel syndrome (IBS) is a common gastrointestinal disorder, which still lacks effective therapy. We aimed to investigate the effects of a novel formulation of Bifidobacterium longum BB536 and Lactobacillus rhamnosus HN001 with vitamin B6 (LBB) on symptoms, intestinal permeability, cultivable bacteria and metabolome in IBS subjects. MATERIALS AND METHODS: Twenty-five IBS patients (Rome IV criteria) (M:F = 8:17; age 48 years ± 11 SD) were randomized to treatment (LBB) or placebo (one month each) in a crossover randomized double-blind controlled trial. Symptoms, intestinal habits, disease severity, intestinal permeability and intestinal microbiota were analysed at 0, 30, 45 and 60 days. RESULTS: Percentage decrease from baseline of abdominal pain (-48.8% vs -3.5%), bloating (-36.35% vs +7.35%) and severity of disease (-30.1% vs -0.4%) was significantly (P < .0001) greater with LBB than placebo, respectively. In IBS-D patients, the improvement from baseline of Bristol score was more consistent with LBB (from 6 ± 0.4 to 4.3 ± 1.1, P < .00001) than placebo (from 6.2 ± 0.7 to 5.3 ± 1.1, P = .04). In IBS-C patients, Bristol score tended to improve from baseline after LBB (2.6 ± 1.1 vs 3.2 ± 0.5, P = .06). LBB significantly improved the percentage of sucralose recovery (colonic permeability) (1.86 ± 0.1 vs 1.1 ± 0.2, P = .01). During treatment, presumptive lactic acid bacteria and bifidobacteria, relative abundance of propanoic, butanoic, pentanoic acids and hydrocarbons increased, while phenol decreased. CONCLUSIONS: The novel formulation of B. longum BB536 and L. rhamnosus HN001 with B6 vitamin improves symptoms and severity of disease, restores intestinal permeability and gut microbiota in IBS patients.