Long lasting immunomodulator effect of a long term of consumption of a specific fermented milk on the intestinal mucosa in a murine model.

CHAVES, S; CARMUEGA, E; WEILL, R; PERDIGON, G

Boston, Massachusetts, USA

Congreso; 12th Internacional Congress of Mucosal Immunology, Boston,; 2005

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 the end 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 IL10, IL2, IL4, IL6, TNFa and INFg by immunofluorescence. Haematoxilin-eosin stain was also performed. Results: We observed continuous oral administration of this fermented milk induced a significant increase in the IgA+ cells in lamina propria of SI and LI, until day 84th. Regulatory cytokines (IL10, IL4) showed significant increase in the most of period assayed, TNFa and INFg producing cells were enhanced until day 70th.IL2 and IL6 showed significant different related to the unfed control in the most of time assayed. The rate CD4/CD8 was maintained during the time assayed. No modifications in the histological studies of the gut were observed. Conclusion: Long term of consumption of this fermented milk containing Lc viable favored the intestinal mucosal immunity, mediated by IgA+ cells and T cell activation. This improvement of the gut mucosal immunity, was maintained and down regulated by the immunoregulatory effect of IL10 or IL4 cytokines, to avoid gut inflammatory immune response.