乳双歧杆菌V9对小鼠免疫功能的影响及机制研究

Immunomodulatory Effects of Bifidobacterium lactis V9 in Mice and its Mechanism

目的评价乳双歧杆菌V9(Bifidobacterium lactis V9)对小鼠免疫功能的调控作用,为其进一步的研发及利用提供实验依据。方法C57BL/6J小鼠随机分为4组,每组10只,分别灌胃给予双蒸水0.5、1.0和3.0 mg/kg乳双歧杆菌V9。30 d后处死小鼠,检测其脏器/体质量比。通过脾淋巴细胞转化、迟发型变态反应来评估各组小鼠的细胞免疫情况;小鼠碳廓清能力和巨噬细胞对鸡红细胞的吞噬功能测定来评估各组小鼠的单核-巨噬细胞功能;溶血空斑实验和血清溶血素水平测定来评估各组小鼠的体液免疫情况;乳酸脱氢酶(LDH)检测来评估各组小鼠的自然杀伤(NK)细胞活力。结果乳双歧杆菌V9对小鼠体质量、脾指数、胸腺指数均无显著影响(P>0.05);乳双歧杆菌V9可显著提高小鼠的脾淋巴细胞转化、碳廓清吞噬指数、单核-巨噬细胞功能、半数溶血值和NK细胞活力(P<0.05)。结论益生菌乳双歧杆菌V9可有效增强机体免疫功能。

Objective Probiotics play an important role in the immune regulation of the body,and different strains often have different regulatory functions on immune cells.The present study aimed to evaluate the immunomodulatory effects of Bifidobacterium lactis V9 in mice and its mechanism.Method Normal C57BL/6J mice were randomly divided into 4 groups(n=10),and intragastrically administrated distilled deionized water,0.5 mg/kg,1.0 mg/kg,and 3.0 mg/kg of Bifidobacterium lactis V9 for 30 days.After that,the mice were killed and the organ/body weight ratio of mice was measured.The cellular immunity was evaluated by splenic lymphocyte transformation assay and delayed hypersensitivity.The function of monocyte macrophage was evaluated by carbon clearance test and mouse peritoneal macrophage phagocytosis of chicken red blood cells.The humoral immunity of mice was evaluated by antibody-producing cell assay and serum hemolysin assay.NK cell activity was evaluated by NK cell activity assay.Result Bifidobacterium lactis V9 showed no significant effects on organ ratios of the mice compared with the negative control(P>0.05).Bifidobacterium lactis V9 significantly increased the transformation ability of mice splenic lymphocytes,murine macrophage carbon clearance function,mouse peritoneal macrophage phagocytosis of chicken red blood cells,hemolytic activity and NK cell activity(P<0.05).Conclusion Bifidobacterium lactis V9 exhibited potent to enhance the immunomodulatory effects,and provide a new idea for its further development and utilization.