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.