Isolation of food-derived bacteria inducing interleukin-22 in B cells.

Recently, we found a novel function of the lactic acid bacterium derived from miso, a fermented soy paste, that induces interleukin (IL)-22 production in B cells preferentially. IL-22 plays a critical role in barrier functions in the gut and skin. We further screened other bacteria species, namely, , , , , , , and , in addition to and found that some of them possessed robust IL-22-inducible function in B cells . This process resulted in the augmented expression of activation markers CD86 and CD69 on B and T cells, respectively. However, these observations were not correlated with IL-22 production. We isolated sc-09 from miso and determined it to be the best strain to induce robust IL-22 production in B cells. Furthermore, feeding sc-09 to mice augmented the barrier function of the skin regardless of gut microbiota.