德氏乳杆菌KY20胞外多糖对C57BL/6小鼠肥胖的预防作用

Preventive Effect of Exopolysaccharide of Lactobacillus delbrueckii KY20 on Obesity in C57BL/6 Mice

为探究德氏乳杆菌(Lactobacillus delbrueckii)KY20及其胞外多糖(exopolysaccharide,EPS)对高脂饮食小鼠肥胖的预防作用,首先对KY20的生长速率、耐酸、耐胆盐活性进行测定,并对其EPS进行提取纯化;采用高脂饮食构建肥胖小鼠模型,设立正常组、模型组、KY20组及其EPS低、中、高剂量组,连续灌胃12周并定期记录小鼠体质量,测定葡萄糖耐量、胰岛素耐量、脏器指数,苏木精伊红染色观察肝脏和脂肪组织变化,试剂盒检测胰岛素、总胆固醇(total cholesterol,TC)、甘油三酯(triglyceride,TG)、高密度脂蛋白胆固醇(high⁃density lipoprotein⁃cholesterol,HDL⁃C)、低密度脂蛋白胆固醇(low⁃density lipoprotein⁃cholesterol,LDL⁃C)含量,气相色谱法检测小鼠盲肠内容物中短链脂肪酸(short chain fatty acids,SCFAs)的含量。结果显示,德氏乳杆菌KY20具有较强的耐酸、耐胆盐能力,并对青霉素、庆大霉素等有敏感性;KY20及其胞外多糖能够降低肥胖小鼠的体质量,改善血脂代谢紊乱,有效抑制高脂饮食诱导的肥胖。

This paper was to explore the inhibitory effect of Lactobacillus delbrueckii KY20 and its exopolysac⁃charide(EPS)on obesity in mice fed with high⁃fat diet.The growth rate and the acid and bile salt resistance of KY20 were measured,and its EPS was extracted and purified.The obese mice model was established by high⁃fat diet,and the mice were divided into normal group,model group,KY20 group and low⁃,medium⁃and high⁃dose EPS groups.The weight of mice was recorded regularly after continuous gavage for 12 weeks,and glucose tolerance(GTT),insulin tolerance(ITT)and organ index were determined.The liver and adipose tissue changes were observed with HE staining.The antibodies to glutamic decarboxylase(GADAb),islet cell anti⁃bodies(ICA),autoantibodies to insulin(IAA),and tyrosine phosphatase⁃like protein IA⁃2(IA⁃2A),as well as triglyceride(TG),total cholesterol(TC),low⁃density lipoprotein⁃cholesterol(LDL⁃C),and high⁃density lipoprotein⁃cholesterol(HDL⁃C)were detected with the kits.Gas chromatography was performed to detect the short chain fatty acids(SCFAs)in the caecum contents of mice.The results showed that L.delbrueckii KY20 had strong acid and bile salt tolerance,and was sensitive to penicillin and gentamicin.KY20 and its EPS re⁃duced the weight of obese mice,improved the disorder of blood lipid metabolism,and effectively inhibited obesity induced by high⁃fat diet.