高脂饮食对不同性别小鼠肠道菌群的影响

Effects of High-Fat Diet on Gut Microbiota in Male and Female Mice

本文以C57BL/6J小鼠为模式动物,研究高脂饮食对不同性别小鼠肠道微生物的影响。16只8周龄SPF级C57BL/6J小鼠,雌雄各半,以基础饲料喂养的小鼠为对照组,45%高脂饲料喂养的小鼠为实验组(每组4只)。饮食干预6周后,收集小鼠新鲜粪便并提取总基因组DNA,通过PCR扩增16S-rDNA的V3+V4区域并进行HiSeq2500高通量测序,分析菌群的组成及丰富度变化。结果显示,高脂饮食改变了小鼠肠道微生物组成及其多样性,在门分类水平上,较之对照组,雌性高脂组小鼠的变形菌门相对丰富度极显著下降(P<0.05),放线菌门相对丰富度显著升高(P<0.01),雄性高脂组小鼠的变形菌门相对丰富度极显著上升(P<0.01),放线菌门相对丰富度无明显变化。在种分类水平上,雌性高脂组小鼠的Lactobacillus_murinus菌种相对丰富度与对照组相比极显著升高(P<0.01),雄性高脂组较之对照组无显著差异。表明高脂饮食对雌性和雄性小鼠肠道微生物组成及结构的影响不同。本研究结果为深入研究饮食及性别因素对肠道微生物的影响提供依据。

In this work,the impact of high fat diet on gut microbiota in the male and female C57BL/6J mice were investigated.Sixteen 8-week-old C57BL/6J mice(8 per sex)were housed in the specific pathogen free(SPF)condition.The mice fed with the normal diet were used as the control groups,fed with the 45%kcal fat diet were used as the experimental groups(4 mice in each group).After 6 weeks of dietary intervention,fresh fecal samples were collected from each mouse.For high throughput Hi Seq 2500 sequencing analysis,fecal bacterial genomic DNA was extracted and amplified based on the V3+V4 region of the bacterial 16S-rDNA gene by PCR(polymerase chain reaction).The changes in composition and relative abundance of gut microbiota were evaluated.The results showed that high-fat diet altered gut microbiota composition,affecting the diversity and similarity.In the female high-fat diet group,the relative abundance of Proteobacteria phylum significantly decreased(P<0.05)and the Actinobacteria phylum significantly increased(P<0.01)compared with the control diet group.However,in the male high-fat diet group,the relative abundance of Proteobacteria phylum significantly increased(P<0.01)and the Actinobacteria phylum had no obvious change compared with the control diet group.Moreover,the relative abundance of L.murinus was significantly higher in the high-fat diet group than that in the control diet group of female mice(P<0.01).However,this species of bacteria did not show significant change in the male high-fat diet group.The effects of high-fat diet on the composition and structure of gut microbiota were different in the female and male mice,these results provide data for further studying the effects of dietary and gender factors on intestinal microorganisms.