Consumption of exogenous bifidobacteria does not alter fecal bifidobacteria and breath hydrogen excretion in humans

Bifidobacterium animalis subsp. lactis HN019 Effects on Gut Health: A Review

Optimal gut motility is central to bowel function and gut health. The link between the gut dysmotility related disorders and dysfunctional-intestinal barriers has led to a hypothesis that certain probiotics could help in normalizing gut motility and maintain gut health. This review investigates the roles of Bifidobacterium animalis subsp. lactis HN019 (B. lactis HN019™) on gut health, and its mechanisms of action in various pre-clinical and clinical studies. Research supports the hypothesis that B. lactis HN019™ has a beneficial role in maintaining intestinal barrier function during gastrointestinal infections by competing and excluding potential pathogens via different mechanisms; maintaining normal tight junction function in vitro; and regulating host immune defense toward pathogens in both in vitro and human studies. This has been observed to lead to reduced incidence of diarrhea. Interestingly, B. lactis HN019™ also supports normal physiological function in immunosenescent elderly and competes and excludes potential pathogens. Furthermore, B. lactis HN019™ reduced intestinal transit time and increased bowel movement frequency in functional constipation, potentially by modulating gut–brain–microbiota axis, mainly via serotonin signaling pathway, through short chain fatty acids derived from microbial fermentation. B. lactis HN019™ is thus a probiotic that can contribute to relieving gut dysmotility related disorders.

Effects of multispecies probiotic supplementation on intestinal microbiota in irritable bowel syndrome

BACKGROUND

A multispecies probiotic has shown beneficial effects in irritable bowel syndrome. In addition, certain other probiotics have demonstrated advantageous effects, but the mechanisms behind this are poorly understood.

AIM

To investigate the mode of action of a multispecies probiotic consisting of Lactobacillus rhamnosus GG, Lactobacillus rhamnosus Lc705, Propionibacterium freudenreichii ssp. shermanii JS and Bifidobacterium breve Bb99 by monitoring its effects on intestinal microbiota and markers of microbial activity.

METHODS

A total of 55 irritable bowel syndrome patients participated in this placebo-controlled double-blind trial. Subjects received either multispecies probiotic or placebo supplementation daily during a 6-month period. The composition of intestinal microbiota was analysed with real-time polymerase chain reaction, short-chain fatty acids with gas chromatography and enzymes with spectrophotometer.

RESULTS

Each supplemented probiotic strain was detected in faecal samples. Intestinal microbiota remained stable during the trial, except for Bifidobacterium spp., which increased in the placebo group and decreased in the probiotic group (P = 0.028). No changes in short-chain fatty acids occurred. A decrease in ss-glucuronidase activity was detected in 67% of the subjects in the probiotic group vs. 38% in the placebo group (P = 0.06).

CONCLUSIONS

Factors other than the microbial groups and metabolites studied herein seem responsible for the alleviation of irritable bowel syndrome symptoms by the multispecies probiotic.

Intra-specific composition and succession of Bifidobacterium longum in human feces

Intra-species analysis of pulsed field gel electrophoresis (PFGE) on human fecal Bifidobacterium longum isolates revealed that a majority of 12 Japanese subjects harbored strains of unique PFGE types or subtypes over a 68-week period, suggesting that "indigenous"Bifidobacterium strains remain stable for a considerable time in each individual intestinal microbiota.