加氏乳杆菌Y20对高胆固醇大鼠模型的降胆固醇效果及对肠道菌群和肝脏代谢的影响

Effects of Lactobacillus paragasseri Y20 on cholesterol-lowering, intestinal microbiota and liver metabolism in rats with hypercholesterolaemia

目的评价加氏乳杆菌Y20对高胆固醇大鼠模型的降胆固醇效果,并探究其潜在机制。方法30只SPF级SD雄性大鼠按体重随机分为3组:空白对照组、高胆固醇模型组和加氏乳杆菌Y20干预组,空白对照组饲喂基础饲料,高胆固醇模型组和Y20干预组饲喂高胆固醇饲料,2周后Y20干预组在饮水中添加3×108 CFU/mL加氏乳杆菌Y20,干预5周。实验结束后,采集血清,使用酶联免疫吸附法检测血脂指标。采集大鼠粪便,提取DNA进行16S rRNA扩增子测序分析。采集大鼠肝脏,使用高效液相色谱法进行非靶向代谢物分析。结果加氏乳杆菌Y20干预组大鼠血清甘油三酯(P<0.05)和低密度脂蛋白(P<0.01)的浓度低于高胆固醇模型组,高密度脂蛋白浓度高于高胆固醇模型组(P<0.05)。高胆固醇饲料会引起大鼠肠道菌群多样性(P<0.01)和丰富度降低,而Y20干预可以部分恢复高胆固醇大鼠的肠道菌群多样性(P<0.05或P<0.01)。高胆固醇饲料引起的肠道菌群改变主要集中在厚壁菌门、脱铁杆菌门、疣微菌门和变形菌门,增加阿克曼菌属、梭状芽孢杆菌_III属和梭状芽孢杆菌_XIVb属的相对丰度(P<0.05),降低Intestinimonas属的相对丰度(P<0.05),Y20的干预能够逆转这些细菌的相对丰度(P<0.05),使之接近正常水平。3组大鼠肝脏代谢谱分为3群,高胆固醇模型组与空白对照组相比,胆汁酸代谢物(如牛磺胆酸、牛磺去氧胆酸等)的相对丰度,以及芥酸酰胺和2,6-二氧(4-14-C)-1,2,3,6-四氢-4-嘧啶羧酸等代谢物的相对丰度,差异有统计学意义。Y20干预组与模型组相比,只有芥酸酰胺和2,6-二氧(4-14-C)-1,2,3,6-四氢-4-嘧啶羧酸的相对丰度差异有统计学意义,且相对丰度的水平接近空白对照组。结论加氏乳杆菌Y20可以有效降低高胆固醇大鼠模型的血脂水平,改善高胆固醇大鼠肠道菌群的多样性和菌群结构,影响大鼠的肝脏代谢水平。

OBJECTIVE To evaluate the cholesterol-lowering effects of Lactobacillus paragasseri Y20 on rats with high cholesterol diet and its effect on the gut microbiota of rats,and to explore the potential mechanism of Lactobacillus paragasseri regulating hypercholesterolemia in rats.METHODS Thirty rats were randomly divided into three groups and were treated with normal diet,high cholesterol diet+PBS,and high cholesterol diet+Lactobacillus paragasseri Y20,respectively.After five consecutive weeks of treatment,serum lipids were measured by ELISA.Rat feces were collected and DNA was extracted for 16S rRNA amplicon sequencing analysis.Rat livers were collected and analyzed for non-targeted metabolites using high performance liquid chromatography.RESULTS Compared with the high-cholesterol model group,Lactobacillus paragasseri Y20 treatment could reduce the serum triglyceride and low-density lipoprotein concentrations and increase the high-density lipoprotein concentration in rats.High-cholesterol diet decreased the intestinal flora diversity and richness of rats,while Y20 intervention can effectively restore the change of intestinal flora of high-cholesterol rats.High cholesterol dietsmainly caused the changes in the relative abundance in phylum of Firmicutes,Deferribacteres,Verrucomicrobia,and Proteobacteria,increasing Akkermansia,Clostridium_III,and Clostridium_XIVbgenera,and decreasing the intestinimonasgenus.However,Y20 intervention restored the diversity of gut microbiota and alteration in relative abundance of these bacteria caused by high-cholesterol diet.Y20 could effectively decrease the higher relative abundance of Akkermansiahigh-cholesterol diet.CONCLUSION Lactobacillus paragasseri Y20 can alleviate hypercholesterolemia in rats,regulate the gut microbiotadiversity and composition and affect liver metabolism in hypercholesterol rats.