适量摄入白兰地对健康大鼠肠道菌群的影响

Effects of moderate intake of brandy on gut microbiota in healthy rats

目的探讨适量摄入白兰地对健康大鼠生理功能及肠道菌群的影响。方法将15只雄性SD大鼠分为对照组(n=7)和白兰地组(n=8),分别以自来水和白兰地进行灌胃,剂量为3.3 mL/kg。灌胃8周后,测定大鼠体质量、体质量增长率、肝脏指数、肝脏抗氧化酶和血清生化指标,并观察肝脏病理切片。灌胃结束时,收集大鼠新鲜粪便样本,应用Illumina-MiSeq测序平台进行16S rRNA基因V3-V4区测序,分析其肠道微生物群落结构、丰富度、多样性及组间差异,同时,对大鼠肠道微生物与生理指标之间的相关性进行分析。结果白兰地组大鼠体质量、进食量、总蛋白、白蛋白、球蛋白、尿素、肌酐/尿素和高密度脂蛋白胆固醇均显著低于对照组(t=2.856、1.152、4.144、4.320、3.393、3.495、3.666、2.223,均P<0.05),且两组肝脏病理切片均未见病理改变。在门水平上,两组大鼠肠道菌群主要由厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)、Candidatus-Saccharibacteria和放线菌门(Actinobacteria)组成,而白兰地组大鼠中放线菌门(Actinobacteria)的相对丰度显著低于对照组(P<0.05),螺旋体门(Spirochaetes)的相对丰度显著高于对照组(P<0.05);在属水平上,白兰地组大鼠肠道中Saccharibacteria_genera_incertae_sedis的相对丰度显著低于对照组(P<0.05)。LEfSe分析显示,螺旋体门(Spirochaetes)、螺旋体科(Spirochaetaceae)、Lactobacillus_johnsonii_F19785、双歧杆菌属(Bifidobacterium)是引起两组肠道菌群差异的主要菌群。与生理指标的相关性分析显示,体质量增长量与Odoribacter和另枝菌属(Alistipes)呈负相关[r=-(0.571~0.566),P<0.05],乳杆菌属(Lactobacillus)与低密度脂蛋白胆固醇呈负相关(r=-0.722,P<0.05),罗斯菌属(Roseburia)与胆固醇和高密度脂蛋白胆固醇呈正相关(r=0.555~0.621,P<0.05),总蛋白与韦荣球菌属(Veillonella)和罗氏菌属(Rothia)呈正相关(r=0.637~0.643,P<0.05),双歧杆菌属(Bifidobacterium)与血清生化检测中的尿素、总蛋白和球蛋白呈正相关(r=0.606~0.653,P<0.05),与肌酐呈负相关(r=-0.612,P<0.05)。结论摄入白兰地对健康SD大鼠生长发育未产生不良影响,也未对大鼠肝脏和肾脏造成损伤,但可显著减缓大鼠体质量增长,且对大鼠某些肠道菌群的丰富度和组成产生一定的影响。

Objective To investigate whether moderate intake of brandy affects physiological functions and gut microbiota in healthy rats.Methods A total of 15 male Sprague-Dawley rats were randomly divided into the brandy group(n=8)or control group(n=7)and given 3.3 mL/kg of brandy or tap water daily by gavage,respectively.After 8 weeks of treatment,the body weight,growth rate of weight,liver index,antioxidant enzyme concentration and serum biochemical parameters were measured,and pathological sections of liver were observed.Fresh fecal samples were collected and 16 S rRNA gene V3-V4 region was sequenced using Illumina-MiSeq platform to analyze the structure,abundance,diversity and inter-group differences of gut microbial community.Pearson correlation analysis was performed to assess the relationship between physiological indexes and gut microbes.Results Body weight,food intake,total protein,albumin,globulin,urea,creatinine/urea and high-density lipoprotein cholesterol in the brandy group were significantly lower than those in the control group respectively(all P<0.05).No pathological changes were observed in the liver tissues in both groups.At the phylum level,Firmicutes,Bacteroidetes,Actinobacteria and Candidatus-Saccharibacteria were predominant,with a higher abundance of Spirochaetes in the brandy group(P<0.05)and a higher abundance of Actinobacteria in the control group(P<0.05).At the genus level,the relative abundance of Saccharibacteria_genera_incertae_sedis in the brandy group was significantly lower than that in the control group(P<0.05).Lefse analysis showed that Spirochaetes,Spirochaetaceae,Lactobacillus_johnsonii_F19785,and Bifidobacterium were the main floras causing differences in gut microbiota between two groups.Analysis of Pearson correlation with physiological factors showed that the weight gain was negatively correlated with Odoribacter and Alistipes[r=-(0.571-0.566),P<0.05],Lactobacillus was negatively correlated with low-density lipoprotein cholesterol(r=-0.722,P<0.05),Roseburia was positively correlated with cholesterol and high-density lipoprotein cholesterol(r=0.555-0.621,P<0.05),and total protein was positively correlated with Veillonella and Rothia(r=0.637-0.643,P<0.05);Bifidobacterium was positively correlated with urea,total protein and globulin in serum biochemical tests(r=0.606-0.653,P<0.05),but negatively correlated with creatinine(r=-0.612,P<0.05).Conclusion Appropriate intake of brandy will not adversely affect the growth and development of healthy SD rats or cause damage to the liver and kidney of rats,but can significantly reduce the body weight gain and has effects on the abundance and composition of certain gut microbes in rats.