宏基因组研究高脂饮食诱导小鼠的肥胖易感性与肠道菌群的关系

目的 考察高脂饮食喂养后小鼠肠道菌群在组成及功能上与肥胖易感的相关性.方法 采用高脂饲料喂养C57BL/6J小鼠构建高脂饮食诱导肥胖组(high-fat-diet-induced-obesity,HFDIO)和高脂饮食诱导肥胖抵抗组(high-fat-diet-induced-obesity-resistant,HFDIOR)模型,正常饲料组为对照组,搜集并提取3组小鼠粪便样本细菌基因组,DNA质检后挑取高质量样本(每组6个),采用Illumina公司的Hiseq2000进行细菌宏基因组测序及相关生物信息学与统计学分析.结果 较之对照组,肥胖组和肥胖抵抗组小鼠肠道厚壁菌门、变形菌门、脱铁杆菌门含量显著升高,拟杆菌门显著下降(P＜0.05).肥胖组和肥胖抵抗组小鼠肠道的特征菌种组成显著不同,且毛螺菌科中的Lachnospiraceaebacterium 10_1与Lachnospiraceae bacterium 28_4分别为肥胖及肥胖抵抗组小鼠的关键菌种;肥胖与肥胖抵抗小鼠肠道菌群的功能及代谢显著差异则主要集中在碳水化合物代谢、核酸代谢与锚定、膜转运活性及转移酶活性等方面.结论 不同个体对于饮食诱导的肥胖的易感性差别可能与肠道菌群组成及功能变化相关,这有助于正确评价肠道菌群在肥胖发生中的作用.

Correlation of gut microbiota with susceptibility to high-fat diet-induced obesity in mice: a metagenomic study

Objective To investigate the correlation between gut microbiota and the susceptibility to high-fat diet-induced obesity in mice.Methods Stool samples were collected from C57BL/6J mice with high-fat diet-induced obesity (HFDIO),mice with resistance to HFDIO (HFDIOR),and normal control mice fed with normal diet.High-quality DNA samples extracted from the stool samples in the 3 groups (n =6) were taken for metagenomic sequencing using Hiseq2000 (Illumina Co.Ltd.).Results Compared with the control group,the mice with HFDIO and HFDIOR showed significantly increased Firmicutes,Proteobacteria and Deferribacteres while obviously decreased Bacteroides in the stool samples (P ＜ 0.05).Significant differences were also found in the species of bacteria between the HFDIO and HFDIOR groups.The dominant species in the microbiota composition was Lachnospiraceae bacterium 10_ 1 in HFDIO group,and Lachnospiraceae bacterium 28_4 was the dominant species in HFDIOR group(P ＜0.05).The functionality and metabolism of the gut microbiota differed between the 2 model groups in terms of carbohydrate metabolism,nucleotide metabolism and nucleic acid binding,membrane transport and transferase activity.Conclusion The composition and function of the gut microbiota may influence the susceptibility of an individual to HFDIO and HFDIOR,which is helpful in assessing the role of gut microbiota in the occurrence of obesity.