Abstract
The immunopotentiating effects of Bifidobacterium longum SBT 2928 (BL2928) were studied in model animals with experimental tumors. BL2928 was selected by mitogenic assay as a potent immunomodulating strain from many food microorganisms including Lactobacillus and Bifidobacterium. When BL2928 was administered systemically, it exhibited marked anti-tumor activity in both allogeneic and syngeneic tumor models. In contrast, administration of carrageenan, an anti-macrophage agent, inhibited the anti-tumor activity of BL2928. Feeding of cultured milk fermented with BL 2928 slightly but significantly prolonged the life span of ICR mice that had been inoculated intraperitoneally with Sarcoma 180. haddition, intragastric incubation of heat-killed BL2928 significantly suppressed the growth of subcutaneously inoculated Sarcoma 180, and also enhanced the delayed-type hypersensitivity responses to sheep erythrocytes in CDF1 mice. Although the degree of anti-tumor effect differed according to the route of administration, BL2928 modified the host immune responses in both the systemic and oral routes.
