BioProject

The modulation of the intestinal microbial ecosystem is considered to be the first target to establish probiotic efficacy in a healthy population. More...

The modulation of the intestinal microbial ecosystem is considered to be the first target to establish probiotic efficacy in a healthy population. A randomized, double-blind, crossover, placebo-controlled intervention study was conducted to determine the impact of the probiotic strain Bifidobacterium bifidum BB on the intestinal microbial ecology of adult healthy volunteers of both sexes. High-throughput 16S ribosomal RNA gene sequencing was used to characterize the fecal microbiota before and after four weeks of daily probiotic cells consumption. This work shows that the intake of one billion live B. bifidum BB cells affects the relative abundance of dominant taxa in the fecal microbiota and modulates the fecal levels of butyrate. Specifically the relative abundance of family Prevotellaceae (P=0.041) and genus Prevotella (P=0.034) was significantly decreased, whereas the relative abundance of families Ruminococcaceae (P=0.039) and Rikenellaceae (P=0.010) was significantly increased. Although the overall composition of the microbiota was not affected, the dependency of the probiotic intervention on the enterotype has been highlighted observing the major effects of BB on microbiota composition in the Prevotella-dominated enterotype rather than the Bacteroides-dominated one. In addition, we observed a normalizing effect on fecal butyrate levels during the probiotic intervention. In conclusion, our study demonstrates that a single daily administration of B. bifidum BB can modify the human intestinal microbial ecology in healthy (not diseased) adults in a significant fashion. These findings can convey the need to reassess the notion of probiotics’ inability to influence the complex and stable intestinal microbial ecosystem of a healthy individual. Less...