Dahi containing Lactobacillus acidophilus and Bifidobacterium bifidum improves phagocytic potential of macrophages in aged mice

The present study investigated the effect of Dahi containing potential probiotic bacterial strains on macrophage functions in ageing mice. Probiotic Dahi was prepared by co-culturing Dahi bacteria ( Lactococcus lactis ssp. cremoris and Lactococcus lactis ssp. lactis biovar diacetylactis ) along with Lactobacillus acidophilus LaVK2 (La-Dahi) or combined L. acidophilus LaVK2 and Bifidobacterium bifidum BbVK3 (LaBb-Dahi) in buffalo milk . The effect of ageing on phagocytic function was evaluated on 4 mo, 12 mo and 16 mo old mice. The effect of probiotic Dahi was evaluated for macrophage functions in ageing mice (12 mo old) fed La-Dahi or LaBb-Dahi supplements for 4 months. The production of extracellular superoxide and H 2 O 2 declined in peritoneal macrophages but enhanced in splenic macrophages, while intracellular superoxide declined in both peritoneal and splenic macrophages with ageing in mice. A decline in phagocytic activity of peritoneal macrophages was also observed in aged mice. Supplementation of diet with La-Dahi or LaBb-Dahi for 4 months improved production of reactive oxygen species and phagocytic and adherence indices of peritoneal macrophages in aged mice. These results suggest that oral administration of La-Dahi or LaBb-Dahi has potential to improve immune functions in ageing individuals.