The effects of Lactobacillus plantarum (L. plantarum) NCU116 isolated from pickled vegetables on intestine mucosal immunity in cyclophosphamide treated mice were investigated. Animals were divided into six groups: normal group (NIM), immunosuppression group (IM), immunosuppression plus L. plantarum NCU116 groups with three different doses (NCU-H, NCU-M, and NCU-L), and plus Bifidobacterium BB12 as positive control group (BB12). Results showed that the thymus indexes of the four treatment groups were significantly higher than that of the IM group (2.02 ± 0.16) (p < 0.05) and close to the index of the NIM group (2.61 ± 0.37) at 10 days. The level of immune factor IL-2 notably increased (IM, 121 ± 9.0) (p < 0.05) and was close to 65% of NIM group's level (230 ± 10.7). The levels of other immune factors (IFN-γ, IL-10, IL-12p70, and sIgA), the gene expression levels of IL-2 and IFN-γ, and the number of IgA-secreting cells showed similar patterns (p < 0.05). However, the level of immune factor IL-4 remarkably decreased (IM, 128 ± 10.2) (p < 0.05) and was only approximately 50% of the NIM group (154 ± 18.2). The levels of other immune factors (IL-6 and IgE) and the gene expression level of IL-6 at 10 days exhibited similar changes (p < 0.05) but showed a slight recovery at 20 days, accompanied by the altered protein expression levels of T-bet and GATA-3 in the small intestine. These findings suggest that L. plantarum NCU116 enhanced the immunity of the small intestine in the immunosuppressed mice.
Keywords: Lactobacillus plantarum NCU116; Th1/Th2 balance; cyclophosphamide; immunomodulation; intestinal mucosal immune.