Probiotic Dahi containing Lactobacillus acidophilus and Bifidobacterium bifidum stimulates immune system in mice

The probiotic Dahi was prepared by co-culturing selected strains of Lactobacillus acidophilus and Bifidobacterium bifidum and Dahi culture (Lactococcus. lactis ssp. cremoris and Lc. lactis ssp. lactis biovar.diacetylactis) in buffalo milk and was evaluated for its effect on immune system. The mice were fed supplements of buffalo milk or probiotic Dahi for 2, 5 or 8 d, and macrophages were evaluated for phagocytic activity and secretion of lysosomal enzymes. The activities of beta-glucuronidase and beta-galactosidase secreted by cultured macrophages, obtained from mice after 2 d of dietary treatment, increased in both buffalo milk and probiotic Dahi groups, however, these were significantly greater in probiotic Dahi group throughout the study. Phagocytic activity of macrophages obtained from buffalo milk group decreased following 8 d of milk supplementation, while a substantial rise in phagocytic activity was observed on probiotic Dahi following 2, 5 or 8 d of product supplementation. The protective effect of probiotic Dahi on intestinal infection was investigated in mice fed the test product for 2 or 7 d and then challenged with Shigella dysenteriae. The colonization of Shigellae in the intestine, liver and spleen was significantly lower in mice on probiotic Dahi than on buffalo milk.