Anti-Inflammatory Properties of Streptococcus salivarius, a Commensal Bacterium of the Oral Cavity and Digestive Tract

Abstract

ABSTRACTStreptococcus salivariusis one of the first colonizers of the human oral cavity and gut after birth and therefore may contribute to the establishment of immune homeostasis and regulation of host inflammatory responses. The anti-inflammatory potential ofS. salivariuswas first evaluatedin vitroon human intestinal epithelial cells and human peripheral blood mononuclear cells. We show that liveS. salivariusstrains inhibitedin vitrothe activation of the NF-κB pathway on intestinal epithelial cells. We also demonstrate that the liveS. salivariusJIM8772 strain significantly inhibited inflammation in severe and moderate colitis mouse models. Thesein vitroandin vivoanti-inflammatory properties were not found with heat-killedS. salivarius, suggesting a protective response exclusively with metabolically active bacteria.