Immunomodulatory effect of probiotic strain Lactobacillus acidophilus M92 in mice

Probiotic bacteria and its components can act on the immune system and increase the body's resistance to infections, cancer and allergy by enhancing the immune response in the host. Therefore, the effect of probiotic strain Lactobacillus acidophilus M92 on the specific and total humoral immune response in Swiss albino mice was studied. Mice were immunized intraperitoneally or orally with a dose of 2.10(10) viable or non-viable cells of L. acidophilus M92. The blood samples were collected 4(th), 8(th), 10(th), 14(th), 17(th) and 21(th) day after first immunization. Sera samples from a] I groups of mice were tested for total and specific anti-lactobacilli IgA, IgG and IgM antibodies with ELISA assay. Irrespective of the way of immunization or bacterial cell preparation. the concentration of total serum IgA, IgG and IgM antibodies from all groups were significantly higher in addition to control groups. The higher levels of specific anti-lactobacilli IgG and IgM antibodies after intraperitoneal (i.p.) than after oral immunization were detected in mice immunized with viable or non-viable cells of L. acidophilus M92. It didn't evoke the specific humoral immune response after oral application and is as such suitable for probiotic application. The results have shown that L. acidophilus M92 has immunomodulatory activity and could be able to protect against various diseases.