Influence of feeding fermented milk and non-fermented milk containing Lactobacillus casei on immune response in mice

The effect of feeding Lactobacillus casei in the form of fermented and non-fermented milk on non-specific as well as humoral immune response in mice was investigated. Feeding of L. casei fermented milk ( LcF), its cell free supernatant ( LcS), and L. casei non-fermented milk ( LcNF) to mice for period of two, five and eight days resulted in increased activity of beta-galactosidase and beta-glucuronidase in peritoneal macrophages in comparison to skim milk ( control). The phagocytic activity of peritoneal macrophages also increased significantly ( p < 0.01) in mice fed on LcF, LcS and LcNF compared to skim milk-fed mice. The maximum rise in beta-galactosidase, beta-glucuronidase and phagocytic activity was on day 5 post-feeding. In challenge studies with Shigella dysenteriae, it was observed that colonization of S. dysenteriae in the intestine, liver and spleen was significantly less in mice fed on LcNF and LcF in comparison to mice fed on skim milk for a period of seven days before challenge. Levels of secretory antibodies were higher in groups fed LcNF and LcF. The results suggest the immunomodulatory potential of L. casei.