双歧杆菌对免疫功能低下小鼠肠道屏障功能的影响

目的了解免疫功能低下小鼠肠道屏障功能并探讨双歧杆菌对其肠道屏障功能障碍的治疗作用。方法选择Balb/c小鼠30只,将其随机分为对照组(A组)、免疫低下组(B组)、双歧杆菌治疗组(C组)。B组及C组以环磷酰胺腹腔注射造免疫低下模型,造模完成后C组应用双歧杆菌进行灌胃治疗。A组以等量生理盐水进行腹腔注射及灌胃。对各组小鼠进行粪便菌群分析、血清二胺氧化酶(diamine oxidase,DAO)测定、小肠黏液分泌性IgA(secretoryimmunoglobulin A,sIgA)测定及肠系膜淋巴结、腹腔灌洗液、肝、肺、肾细菌培养以测定细菌易位率。结果与A组、C组相比,B组小鼠粪便中益生菌双歧杆菌及乳酸杆菌含量显著下降、条件致病菌大肠杆菌与类杆菌含量增加,血清DAO升高,小肠sIgA含量下降,细菌易位率升高(P<0.05);A组与C组各指标比较差异无统计学意义(P>0.05)。结论免疫功能低下小鼠肠道机械屏障、免疫屏障、生物屏障均受损,而双歧杆菌可从上述各方面改善肠道屏障功能,对于难治性菌群失调及细菌易位有治疗作用。

Effect of bifidobacterium on gut barrier function of mice with hypoimmunity

Objective To investigate the gut barrier function of mice with hypoimmunity and the effect of bifidobacterium on intestinal barrier functional disturbance.Methods Thirty BALB/c mice were randomly divided into 3 groups with 10 mice in each group.The mice in group B and C were intraperitoneal injected with cyclophosphamide.The mice in group C were given intragastrical bifidobacterium.The intestinal microbial flora was detected by culturing the feces.The secretory immunoglobulin A in intestinal mucus and the diamine oxidase in blood serum were analyzed by ELISA.The mesenteric lymph nodes,homogenated tissues of the lives,lungs,kidneys used for peritoneal lavage were cultured to determine bacterial translocation.Results The numbers of Lactobacillus and Bifidobacterium in group B were lower than those in group A and C.In contrast,the numbers of Enterobacteriaceae and Bacteroides fragilis were higher than those of group A and C（P0.05）.Conclusion There were intestinal barrier functional disturbance in mice with hypoimmunity.Bifidobacterium could coordinate the immunologic function,cure the alteration of intestinal flora,and protect the gut barrier function.