嗜酸乳酸杆菌对实验性溃疡性结肠炎治疗的最佳浓度探索及免疫学机制初探

摘要

目的:比较不同浓度嗜酸乳酸杆菌治疗实验性溃疡性结肠炎(ulerative colitis,UC)的疗效,分析其对结肠近、远端菌群的影响,寻找治疗UC适宜的嗜酸乳酸杆菌浓度,并探索其免疫学机制.方法:雌性Balb/c小鼠56只,随机分为7组(n=8),葡聚糖硫酸钠(DSS)造UC模型鼠,分别予以不同浓度嗜酸乳酸杆菌、激素、生理盐水干预UC模型鼠,观察小鼠一般情况,计算疾病活动指数(DAI) 评分、组织损伤评分,留取小鼠肠道组织进行肠道固生菌群分析,并进行PCR及Western-Blotting检测UC相关的IL-23、IL-17、TNF-α.结果:106 CFU/mL浓度级嗜酸乳酸杆菌干预组小鼠UC症状缓解最明显,且远端结肠益生菌(乳酸杆菌和双歧杆菌)数量最多,致病菌(金黄色葡萄球菌)最低;UC相关的IL-23、IL-17、TNF-α无论mRNA水平还是蛋白质水平,均为嗜酸乳酸杆菌干预组最低,尤其以106 U /10 g 嗜酸乳酸杆菌灌胃组最低.结论:嗜酸乳酸杆菌治疗UC与其在结肠远端有较高浓度乳酸杆菌有关,然而疗效并非与细菌浓度完全正相关,炎性因子 IL-23、IL-17、TNF-α与UC疾病严重程度呈正相关,与嗜酸乳酸杆菌对UC的治疗作用相关.%Objective:To compare the effect of different concentration of Lactobacillus acidophilus (L.acidophilus) on ulerative colitis (UC),and to analysis the influenceof of proximal and distal colon of bacteria,to find the appropriate concentration of L.acidophilus for UC,and to explore the immunological mechanism.Methods:56 female Balb/c mice were randomly divided into 7 groups (n=8),dextran sulfate sodium (DSS) made of UC model rats were given different concentration of L.acidophilus, hormones,physiological saline intervention UC model rats,observed the general condition of the mice,calculated the disease activity index (DAI) score,tissue injury score,the intestinal flora of mice was taken for intestinal flora analysis,and PCR and Western-Blotting were used to detect UC related IL-23,IL-17,TNF-α.Results:In the 106CFU/mL concentration group,the UC symptoms relief of the L.acidophilus intervention group were the most obvious,and the number of probiotics (lactobacillus and bifidobacteria) in the distal colon was the most,and the pathogen (staphylococcus aureus) was the lowest.UC related IL-23,IL-17,TNF-α regardless of mRNA level or protein level,were lowest in the L.acidophilus intervention group,especially in the 106 U /10 g L.acidophilus gavage group.Conclusion:L.acidophilus UC and its treatment in the distal colon have higher concentrations of lactic acid bacteria,but the result is not completely positive correlation with the concentration of bacteria,inflammatory factor IL-23,IL-17 and TNF-α are positively correlated with the UC disease severity,associate with the therapeutic effect of L.acidophilus on UC.