肠道菌群介导饮食对于肥胖表型的作用

 目的 探索肠道微生物与饮食以及肥胖表型之间的关系。方法 2019年8月在上海复旦大学江湾校区纳入8名自我报告健康的志愿者。使用双能X射线吸收法测量研究对象的肥胖表型数据，通过面对面询问的方式收集3天24 h饮食回顾数据，并采集志愿者的粪便样本。对肠道微生物进行核酸提取和宏基因组文库的构建，并运用鸟枪法宏基因组二代测序技术分析志愿者肠道菌群特征；对志愿者进行肠型分析和饮食结构分析；最后综合探讨肠道菌群与饮食结构及肥胖表型之间的关系。结果 8名志愿者（6名男性、2名女性）年龄为22~28岁，根据肠道内的细菌种类和数量，志愿者可分成两种肠型：拟杆菌型和普氏菌型。肠道菌群和饮食结构之间具有显著的相关性（P=0.01）。普氏菌型的志愿者食用更多的十字花科蔬菜、精加工谷物和全谷物。线性相关分析表明，相对丰度前20的菌属或菌种与肥胖表型之间存在相关性，其中拟杆菌属（Bacteroides）、普通拟杆菌（Bacteroides vulgatus）的相对丰度与躯干脂肪含量、全身脂肪含量呈正相关；普氏菌属（Prevotella）或人体普氏菌（Prevotella copri）的相对丰度与躯干脂肪含量、腰腹部Android区域脂肪含量、髋部Gynoid区域脂肪含量和全身脂肪含量呈负相关。结论 肠道菌群可能介导饮食对于肥胖表型的作用。

The effect of diet mediated by gut microbiota on adiposity phenotypes

Objective To explore the association among gut microbes, dietary structure, and adiposity phenotypes. Methods In Aug 2019, 8 self-reported healthy subjects were recruited at Jiangwan Campus of Fudan University in Shanghai. Obesity phenotype data of the subjects were measured by dual-energy X-ray absorption measurement. Their 3-day, 24-hour diet recall questionnaires data were collected through face to face interviews and their fecal samples were also collected. Then, DNA extraction, metagenomic library construction, and whole-genome shotgun sequencing of gut microbiome were conducted to analyze the characteristic of gut microbiome. Meanwhile, enterotype analysis and diet structure analysis were conducted from subjects. Finally, we generally analyzed the relationship among gut microbiome, dietary structure and obesity phenotype. Results The 8 volunteers (6 men and 2 women) aged 22-28 years. According to the community composition, 8 volunteers were clustered into two enterotypes of Bacteroides and Prevotella, respectively. Further analyses indicated a significant association between dietary structure and gut microbiome (P=0.01). Prevotella enterotype volunteers had more cruciferous vegetables, refind grains and whole grains intake. Linear correlation analysis showed that the relative abundance of the top 20 genera and species had correlation with adiposity phenotypes. The relative abundances of Bacteroides or Bacteroides vulgatus were positively associated with adiposity phenotypes such as trunk fat and total body fat, and those of Prevotella or Prevotella copri were associated negatively with trunk fat, Android region fat, Gynoid region fat and total body fat. Conclusion Gut microbe may mediate the effect of diet on the adiposity phenotypes.