Immune modulation effects of soya bean fermentation food evaluated by an animal model

A murine model was used to evaluate the role of soya bean fermentation broth (SFB) in immune-modulating a T helper type 1 (Th1)/T helper type 1 (Th2) response. The SFB feeding groups (0.1% and 0.4%) had significantly increased T-cell proliferation (47.4 ± 2.5% and 48.2 ± 5.6%, respectively) in the third week compared with the control group (43.3 ± 2.5%), and also significantly enhanced natural killer (NK) cell activity (33.2 ± 4.2% and 35.1 ± 5.9%, respectively) compared with the control group (24.8 ± 4.8%). The IL-2 concentrations of sera were 236.3 ± 4.3 and 251.3 ± 35.4 pg/10⁶ cells in the SFB feeding groups respectively, which were almost double higher than the control group 144.1 ± 23.1 pg/10⁶ cells. Conversely, the IL-4 concentration in sera was significantly decreased when stimulated by the mitogen concanavalin A (2 μg/ml) in SFB feeding group. The ratio of IL-2 to IL-4 in the SFB groups was 10.4 and 17.6, respectively, which was higher than that in the control group (4.7). The SFB is proposed to have the potential to induce T-cell proliferation and enhance the function of Th1 cells, then increased the secretion of IL-2, which enhanced NK cell activity. We suggest that the SFB might be a good resource for modulating immunity in human health care.