“THE PROBIOTIC BACTERIA LACTOBACILLUS CASEI INDUCES ACTIVATION OF THE GUT MUCOSAL IMMUNE SYSTEM THROUGH THE INNATE IMMUNITY.”

MARIA CAROLINA MALDONADO GALDEANO; GABRIELA PERDIGÓN

Clinical and Vaccine Immunology.

American Society for Microbiology

Año: 2006 vol. 13 p. 219 - 226

1556-6811

The mechanisms by which probiotic bacteria affect the immune system are unknown yet, but many of them are attributed to an increase in the innate or in the acquired immune response. To study the influence of the probiotic bacterium L. casei in the expression of receptors involved in the innate immune response, this bacterium was orally administered to BALB/c mice. After, they were sacrificed; the small intestine and intestinal fluids were collected to measure secretory IgA specific for L. casei. Mononuclear cells from Peyer’s patches were isolated to determine the CD-206 and TLR-2 receptors. In histological slices we determined the number of IgA+, CD4+, CD8+ and CD3+ cells and two cytokines (IL-5 and IL-6). CD-206 and TLR-2 increased with respect to the untreated control. We did not observe an increase in the T population or in the IL-5 positive cells. IgA+ cells and IL-6 producing cells increased after 7 days of L. casei administration. We did not find specific antibodies against L. casei. The main immune cells activated after oral L. casei administration were those of the innate immune response, with an increase in the specific markers of these cells (CD-206 and TLR-2), with no modification in the number of T cells.