乳杆菌对致病性大肠杆菌感染小鼠肠黏膜屏障功能的影响

目的:研究乳杆菌对致病性大肠杆菌感染小鼠肠黏膜屏障的保护作用.方法:将BALB/c小鼠随机分为对照组、致病性大肠杆菌感染组、乳杆菌JCM1081灌胃组、乳杆菌治疗组等,实验进行14 d.观察各组小鼠肠黏膜形态变化、肠道菌群变化、细菌移位以及肠黏膜钙黏蛋白表达的差异.结果:致病性大肠杆菌感染组小鼠与对照组相比,肠黏膜形态有明显改变,肠道内厌氧菌数量显著下降,肠杆菌和肠球菌数量明显增加,在肝、脾、肾以及肠系膜淋巴结中有细菌存在,但肠黏膜钙黏蛋白无明显变化.乳杆菌灌胃组小鼠各项指标无显著变化.乳杆菌治疗组小鼠各项指标变化程度较致病性大肠杆菌感染组显著减轻.结论:乳杆菌能黏附定植于肠黏膜并形成生物屏障,起着保护肠黏膜免受损伤的作用.

Effect of Lactobacillus in the intestinal barrier function on enteropathogenic Escherichia coli infected mice

Objective: To investigate the effect of Lactobacillus on the intestinal barrier function in enteropathogenic Escherichia coli infected mice.Methods: Sixty SPF BALB/c mice were randomly divided into six groups.The morphology of mucosa,gut microflora analysis,intestinal bacterial translocation and expression of mucosal ECD were observed for intestinal mucosal changes.Results: Compared to the normal control group,there were obvious pathological changes of mucosal morphology in the EPEC infected mice.Additionally,the number of Enterobacteria and Enterococcus increased significantly,but the number of anaerobic bacterium such as Bifidobacteria and Lactobacillus decreased and the ratio of anaerobes to aerobes declined.The degree of dysbiosis in Lactobacillus treatment group was much less than that in EPEC-infected group,as well as the rate of bacterial translocation.There was no significant change in ECD expression between the groups.Conclusion: Lactobacillus reuteri JCM1081 has ability to adhere and colonize to intestinal mucosa and form biologic barrier to enhance host resistance against enteropathogenic Escherichia coli infection.