The aim of this study was to investigate effects of Lactobacillus brevis KB290 (KB290) containing beverage (over 6.0×109 cfu) on bowel movement and on intestinal environment of healthy volunteers with a tendency toward constipation.
A randomized, double-blind, placebo-controlled, cross-over trial was performed in 64 healthy volunteers with 2 to 5 bowel movements per a week (analysis subject number: 56 [19 males, 37 females], 44.9±8.9 years old [average±SD]). Intake of the KB290 beverage for 2 weeks significantly increased the number of days with defecations, and improved stool color and feeling after defecation. Changes in those parameters were significantly larger in the group consuming the KB290 beverage compared with the placebo beverage. Microbiome analysis by RT-PCR method revealed significant increase of Lactobacillus group (p＜0.001) and the changes in fecal propionate was higher in the KB290 beverage (p＝0.045). Comprehensive microbiome analysis by next generation sequencer method detected significant changes in the ratio of some bacteria such as an increase of Anaerostipes (p＝0.002), a butyrate-producing bacterium.
In conclusion, our results suggest that intake of alive KB290 improves human bowel movements via enhancing short-chain fatty acid production by intestinal microbiota.)