IMMUNE-RESPONSE OF MICE TO ORALLY-ADMINISTERED LACTIC-ACID BACTERIA

In order to elucidate the interaction of lactic acid bacteria with the immune system, immune responses to the lactic acid bacteria, Bifidobacterium longum and Lactobacillus acidophilus, were examined in mice fed with each organism. In mice fed with B. longum for more than 8 weeks, an antibody response was detected to the cytoplasm of B. longum, but not to the cell wall. On the other hand, in mice fed with L. acidophilus for more than 6 weeks, an antibody response was detected to both the cytoplasm and cell wall of L. acidophilus. Moreover, feeding each organism for 2 weeks enhanced the proliferative response of Peyer's patch (PP) cells to the cell fraction against which the serum antibody was detected. However, this was not found with spleen cells. These results suggest that mucosal stimulation by lactic acid bacteria may induce a systemic immune response to them.