Anti-inflammatory effect on colitis and modulation of microbiota by fermented plant extract supplementation

Although results of recent studies suggest that fermented foods strongly affect the gut microbiota composition and that they relieve inflammatory bowel disease symptoms, some reports have described that fermented foods increase some inflammation markers based on differences in fermented food materials. This study evaluated the effects of fermented plant extract (FPE) on dextran sulfate sodium (DSS)-induced colitis in mice and the effects on fecal microbiota composition in humans. Mice fed 5% FPE with 3% DSS (FPE group) showed no body weight loss, atrophy of colonic length, or bloody stool, similar to mice fed a basal diet (negative group), whereas mice fed 3% DSS (positive group) exhibited those effects. Concentrations of inflammation markers IL-6 and TNF-α were not significantly different between FPE and negative groups; however, those concentrations became higher in the positive group. 16S ribosomal RNA gene sequencing was used to characterize fecal microbiota in healthy women before and after 3-month FPE supplementation. The FPE supplementation induced increases in Firmicutes phyla and in Clostridiales order, which play a central role in inflammation suppression. These results suggest that FPE enhances Clostridiales growth in the gut and that it has an anti-inflammatory effect.