Co-Culture with Improves the Growth, Gut Colonization, and Butyrate Production of : In Vitro and In Vivo Studies.

is a major commensal bacterium in the human gut. It produces short-chain fatty acids that promote intestinal health. However, the bacterium is extremely oxygen-sensitive, making it difficult to develop as a probiotic. To facilitate practical application of , we investigated factors that affect its growth and mammalian gut colonization. We evaluated cross-feeding interactions between and seven strains, and the anti-inflammatory properties of bacterial metabolites produced in co-culture, in vitro and in vivo. Co-culture of and , with fructooligosaccharides as an energy source, resulted in the greatest viable cell-count and butyrate production increases. Further, the co-culture supernatant reduced the amount of proinflammatory cytokines produced by HT-29 cells and RAW 264.7 macrophages, an effect that was similar to that of butyrate. Furthermore, feeding mice both and enhanced gut colonization. Finally, feeding the co-culture supernatant decreased interleukin 8 levels in the colon and increased butyrate levels in the cecum in the dextran sodium sulfate-induced colitis mouse model. These observations indicate that the - co-culture exerts an anti-inflammatory effect by promoting survival and short-chain fatty acid production, with possible implications for the treatment of inflammatory bowel disease.