Protective Effect of Orally Administering Immune Milk on Endogenous Infection in X-Irradiated Mice

The protective effect of orally administering immune milk, which was obtained from cows immunized with a mixture of various bacteria, on radiation-induced lethality was studied in mice exposed to a lethal dose of irradiation. The mice were given immune milk or control milk for 7 days, exposed to X-irradiation, and then given either milk daily to the end of the observation period. The irradiated mice given immune milk showed a higher survival rate than the irradiated mice given control milk. The number of Enterobacteriaceae in the feces was almost the same in both groups of mice, whereas the number of Lactobacilli was higher in the mice given immune milk. The concentration of IgA in the supernatant of a cell culture derived from Peyer’s patches, mesenteric lymph node and spleen was higher in that prepared from the mice given immune milk than in that prepared from the mice given control milk. The activity of Kupffer cells for bacterial killing in vivo was higher in the mice given immune milk than that in the mice given control milk. Bacteria in the liver after irradiating appeared in a lower number in the mice given immune milk than in the mice given control milk. These results suggest that immune milk prevents mice from endogenous infection by augmenting the defense activity against the invasion of intestinal bacteria.