Immune modulation promoted by probiotic fermented milk in the mucosal immune system in an experimental model of allergy

VELEZ, EVA MARIA; MALDONADO GALDEANO, CAROLINA; MESÓN, OSCAR; BIBAS BONET, M EUGENIA; CARMUEGA, E; WEILL, RICARDO; PERDIGON, GABRIELA

Palmas de Mallorca

Workshop; 6th International Immunonutrition Workshop; 2012

Intestinal microbiota has an essential role in the maturation and function of the immune system. Changes in the microbiota, together with genetic factors induce the development of allergy with a typical Th2 profile(1). Probiotics can stimulate the mucosal immune system and improve the composition of the microbiota (2), hence the oral administration of probiotics is proposed to avoid the development of allergies by balancing the microbiota and the immune system,at the intestinal mucosa, bronchus and at systemic level (3). The aim of this work was to evaluate the adjuvant immune effect of the administration of a probiotic fermented milk (PFM) in the intestinal mucosa and the extent of these effects to distant mucosal sites (bronchus) in an experimental mouse model of allergic airway reactivity to ovoalbumin (OVA). Experimental groups: normal-control (NC), Basal (B-5days-PFM); OVA-Sensitization-control (SC), Previous (P) (5d-PFM+OVA+H2O) and Continuous (C) (5d-PFM+OVA+PFM). SC, P and C were sensitized with OVA 1% followed by daily exposures to OVA aerosols. At 7 and 15 days post-sensitization (dps) we analyzed: specific-IgE, specific-IgG and IL-10 in serum, total S-IgA, IL-10 and IFN-g in intestinal fluid (IF), specific- IgE in bronchoalveolar lavage (BAL) by ELISA. Determination of the number of IgA +, IL-10 + and IL-4 + cells in the lamina propria of small intestine (SI) and lungs by immunofluorescence assay. In large intestine (LI) we determine total populations of total anaerobes, lactobacilli, bifidobacteria and enterobacteria in selective media. Specific IgE was significantly reduced in P and C groups with regard to SC group in serum and BAL. Specific IgG increased in all groups but had higher values in C compared to SC. IL-10 values increased only in SC group in SI fluid compared to treated groups, but had no changes in serum. IFN-g levels had no significant difference between groups in SI fluid. Total S-IgA from SI fluid significantly increased in CS a P groups compared to NC, B and C groups. IL-4 + cells increased significantly in SC group in lungs with regard to the other groups at 7 and 15 dPS; in SI we found no differences between controls and treated groups. The number of IL-10 +cells was significantly higher in the lamina propria of SI from SC group compared to P and C at 7 and 15 dPS. PFM induced a decrease of enterobacteria and increase of bifidobacteria only in C group, other populations were not affected. PFM was able to reduce the levels of specific IgE in serum and BAL in mice with continuous treatment; this could be mediated by the regulation of the intestinal microbiota that might have influence on the expression of cytokines IL-4 (Th2 type) and IL-10 (regulatory cytokine) at the mucosal level (intestine and lungs). However systemic and mucosal normal immune response was not affected because IgG and S-IgA production was not altered by the IL10