Oral administration of multiple lactic acid bacteria strains suppressed allergic responses IgE in an ovalbumin-induced allergy BALB/c mouse model

The aim of this study was to evaluate the immunomodulatory effect of probiotics, namely the production of interferon γ (IFN-γ) and interleukin-4 (IL-4) cytokines, in vitro and in vivo. Our experimental groups included ten lactic acid bacterial (LAB) strains, complex strains, a LAB cell free fraction and a control group. Our models included human peripheral blood mononuclear cells (PBMCs) as the human model and BALB/c mice as the animal model. The experiment was carried out over a period of 4 weeks during which the food intake and the body weight of our animal model was reported weekly. BALB/ c mice were randomly divided into three groups and injected with 2 µg/ mouse and 6 µg/ mouse ovalbumin (OVA) mixed with complete Freund’s adjuvant (CFA) at week zero and two. After week four the serum total immunoglobulin E (IgE) was measured. The results show that probiotic products induced IFN-γ, suppressed IL-4, and increased the IFN-γ/ IL-4 (Th-1/ Th-2) ratio significantly in PBMCs. Probiotic products also decreased significantly the serum total IgE and OVA-specific IgE levels in our animal model. Our study indicates that the multi-species probiotics may therefore have an anti-allergy effect.   Key words: Probiotics, human peripheral blood mononuclear cell, cytokines, immunoglobulin E, anti-allergy effect.