Therapeutic effects of a fermented soy product on peanut hypersensitivity is associated with modulation of T-helper type 1 and T-helper type 2 responses

Background: ImmuBalance™ is a koji fungus (Aspergillus oryzae) and lactic acid fermented soybean product. This unique production process is believed to create a food supplement that helps to induce or maintain normal immune response. Objective: To assess possible therapeutic effects of ImmuBalance™ on peanut (PN) hypersensitivity using a murine model of peanut allergy (PNA). Methods: PN allergic C3H/HeJ mice were fed standard mouse chow containing 0.5% or 1.0% ImmuBalance (ImmuBalance 2X), radiation-inactivated 1.0% ImmuBalance (I-ImmuBalance 2X), or regular diet chow (sham) for 4 weeks, beginning 10 weeks after the initial PN sensitization, and then challenged with PN. Anaphylactic symptom scores, plasma histamine, serum PN specific-IgE levels and splenocyte cytokine profiles were determined. Results: While 100% of sham-treated PNA mice developed anaphylactic reactions with a median score of 3.3 following PN challenge, only 50% of ImmuBalance, 30% of ImmuBalance 2X and 40% of I-ImmuBalance 2X-treated mice developed allergic reactions with median scores of 1.0, 0.4 and 0.5 respectively, which were significantly less than that in the sham-treated mice (P<0.05). Plasma histamine and PN specific-IgE levels were also significantly less in all treated mice than in sham-treated mice (P<0.05). Furthermore, IL-4, IL-5 and IL-13 production by PN-stimulated splenocytes in vitro from ImmuBalance fed mice were markedly reduced compared with sham-treated mice, whereas IFN-γ production was moderately increased. TGF-β and TNF-α production were similar. Conclusions: ImmuBalance protects against PN-induced anaphylaxis when administered as a food supplement in this model. Protection was associated with down-regulation of Th2 responses. This supplement may provide a potential novel therapy for PNA.