中文摘要：

哺乳动物的消化道居住着数以万亿的,数千种共生微生物或者肠道菌群。肠道菌群与动物宿主通过共进化而共生并经过相互作用而影响其生理与病理生理过程。胆汁酸、胆碱、膳食纤维及芳香类代谢物等多种物质的共代谢是该相互作用的关键分子过程,肝肠循环是上述物质交换与调控相互作用的主要途径。肠道菌群组成与代谢组的关系及其功能的精确刻画是急需解决的科学问题。

英文摘要：

Trillions of microbes also known as gut microbiota live in the gastrointestinal tract（GIT） of mammals with more than two thousands species. These gut microbiota and their mammalian hosts undergo close interactions to form symbiotic ＂superorganisms＂ through co-evolution, contributing towards the physiological and pathophysiological processes of mammals. Co-metabolisms of bile acids, choline and carnitines, dietary fibers and aromatic compounds are the major host-microbial interactive exchanges of bioactive metabolites whilst enterohepatic recirculation is the major route for such exchanges and regulations. Accurate definition of the gut microbiota, metabolite composition and their functional relationships is urgently required for further understanding the host-micriobiota interactions and implication in mammalian health.