The effect of Lactobacillus johnsonii Ncc533 (La1) on the balance of Th1/Th2 cells in BALB/c mice

Purpose To determine the effect of Lactobacillus johnsonii Ncc533 (La1) on Th1/Th2 balance, the production of IL-4 and IFN-γ by splenocytes was evaluated following its administration to mice from newborn to adult. Changes in IL-4 and IFN-γ expression and serum levels of OVA-specific-IgE were then investigated in an asthma model. Methods Using flow cytometry (FCM) and ELISA, the percentage of IL-4 and IFN-γ expressing splenocytes and serum levels of OVA-specific-IgE were measured in different groups of mice. Results The percentages of IL-4 and IFN-γ expressing splenocytes in the offspring and in the adults of the La1-treated group were not significantly different when compared with the water-treated group. In the asthma model, the percentages of IL-4 expressing cells and the serum levels of OVA-specific-IgE in the La1-treated and water-treated group were significantly increased compared with those in the control group. The percentage of IFN-γ expressing cells was significantly lower in the La1-treated and water-treated groups. The percentage of IL-4 expressing cells and the serum levels of OVA-specific-IgE in the La1-treated group were significantly lower compared with those in the water-treated group, whereas the percentage of IFN-γ expressing cells was significantly higher. Conclusion Administration of La1 had no effect on the immune system from the neonate to the adult in the normal mice. It did, however, significantly alter the percentages of IL-4 or IFN-γ expressing CD4+ T lymphocytes in the asthma model, suggesting that administration of La1 might regulate the immune response.