Low doses of allergen and probiotic supplementation separately or in combination alleviate allergic reactions to cow beta-lactoglobulin in mice.
Joyce Boye , Thang, C. L., and X. Zhao
Nom de la revue: Journal of Nutrition 143(2): 136-41.
Probiotic supplementation and oral tolerance induction can reduce certain types of food allergy. The objectives of this study were to investigate the allergy-reducing effects of probiotics (VSL#3) and/or oral tolerance induction via low doses of an allergen supplementation in beta-lactoglobulin (BLG)-sensitized mice. Three-week-old, male BALB/c mice were divided into 6 groups (n = 8/group): sham-sensitized negative control (CTL-), BLG-sensitized positive control (CTL+), oral tolerance-induced and BLG-sensitized group (OT), probiotic-supplemented OT group (OTP), probiotic-supplemented CTL- (PRO), and probiotic-supplemented and BLG-sensitized (PROC) groups. Mice were i.p. sensitized with BLG and alum and then orally challenged with BLG. Immunological responses were assessed by monitoring hypersensitivity scores and measuring levels of BLG-specific serum Igs, total serum IgE and fecal IgA, and cytokines from serum and spleen lysates. Hypersensitivity scores were significantly lower in the PROC (2.00 + 0.53), OT (0.75 + 0.46), and OTP mice (1.00 + 0.53) than in the CTL+ mice (2.63 + 0.52) as were BLG-specific serum IgE concentrations (34.3 + 10, 0.442 + 0.36, 3.54 + 3.5, and 78.5 + 8.7 mug/L for PROC, OT, OTP, and CTL+, respectively). Our results suggest that supplementation of VSL#3 suppressed the allergic reaction mainly through increased intestinal secretary IgA (sIgA) in PROC mice, and oral tolerance offered allergen-specific protective effects to BLG-induced allergy, probably through CD4+CD25+ regulatory T cell-mediated active suppression. In OTP mice, probiotics did not induce a further reduction of hypersensitivity score compared with OT mice but may provide additional protection to unforeseen nonspecific challenges through increased intestinal sIgA.