Immunomodulatory effect of long term fermented milk consumption on the intestinal immunity in a murine model

CHAVES, S., CARMUEGA, E, WEILL, R., PERDIGÓN, G.

Boston, Massachusetts. USA

Congreso; 12th International Congress of Mucosal Immunology.; 2005

Society for Mucosal Immunology

Background: The Lactobacillus casei (Lc) is common probiotics strain used in fermented foods to balance disturb in the intestinal microflora and in dysfunction of the human gastrointestinal tract. Methods: We investigated the effect of the prolonged administration of a fermented milk containing Lc, in the gut mucosal response. BALB/c adult mice were fed with a conventional balanced diet ad libitum and the test group was fed with fermented milk (108 CFU/day/mouse) for 14th weeks consecutively. The samples were taken at 2, 5, 7, 10 and 14 days after that they were taken each two weeks until end the of assay. Small and Large Intestine (SI, LI) were removed at the end of each period of time for histological slices preparation. We measured IgA+ cells, CD4+ and CD8+ T Lymphocytes and cytokines producing cells for IL10, IL2, IL4, IL6, TNFa and INFg by Immunofluorescence. Haematoxilin-Eosin stain was also performed. Results: We observed that continuous oral administration of this fermented milk induced a significant increase in the IgA+ cells in lamina propria in SI and LI, until day 84th. Regulatory cytokines (IL10, IL4) showed significant increase in the most of periods assayed, TNFa and INFg producing cells were enhanced until day 70th.IL2 and IL6 showed significant differences related to the unfed control, in the most of the periods assayed. The rate CD4/CD8 was maintained during the time assayed, with slight, but not significant, variations related to the control values. No modifications in the histological studies of the gut were observed. Conclusion: Long term of consumption of a fermented milk containing Lc viable probiotic microorganisms favoured the intestinal mucosal immunity, mediated by IgA+ cells and T cell activation. This improved gut mucosal immunity was maintained and down regulated by the immunoregulatory effect of the IL10 or IL4 cytokines, avoiding gut inflammatory immune response.