Novel probiotics isolated from a Japanese traditional fermented food, Funazushi, attenuates DSS-induced colitis by increasing the induction of high integrin αv/β8-expressing dendritic cells.

BACKGROUND: We isolated two novel probiotics strains (s193 and s292) from Funazushi, which is a traditional Japanese fermented food, and evaluated its effects on DSS-induced colitis to determine the possible underlying mechanisms.

METHODS: A single colony from homogenized Funazushi was isolated by its ability to suppress TNF-α in RAW 264.7. Effect of probiotics on colonic inflammation induced by DSS was evaluated. Effect of probiotics on Treg induction by CD11c+ dendritic cells (DCs) of MLNs were analyzed.

RESULTS: Two novel probiotics strains classified into the genus Lactobacillus were isolated (s193 and s292), and those strains showed stronger anti-inflammatory effects on DSS-induced colitis than those of L. gasseri isolated from the gut. mRNA expression β8 integrin in CD11c+ DCs of MLNs and the number of Tregs in the large intestine were significantly increased by s193 and s292 administration compared with L. gasseri administration. Bone marrow DCs treated with s193 and s292 highly increased β8 integrin, and those cells strongly induced differentiation of CD4+ T cells into Tregs. Differentiation of Tregs was remarkably inhibited by anti-β8 integrin antibody treatment.

CONCLUSIONS: Strains s193 and s292 demonstrate strong anti-inflammatory effects on DSS-induced colitis through induction of β8 integrin expression on DCs. Our results suggested that Japanese traditional fermented foods are valuable sources for probiotics that are effective for IBD therapy and treatment.