“肠道菌群-SCFAs-DNA甲基化”途径调控痰湿体质代谢紊乱的作用机制研究

The high incidence of metabolic diseases is an urgent global public health issue today, through the perspective of phlegm-dampness constitution (PC) in Chinese medicine can provide new approaches for the prevention of multiple metabolic diseases. PC is the soil of many metabolic diseases according to the Chinese medicine theory. Our previous studies revealed that phlegm-dampness constitution demonstrated metabolic disorder related DNA methylation profiles even in the un-diseased stage. However, the mechanism of the distinct DNA methylation characteristics in PC is not yet clear. Enteric microbiota is an important epigenetic regulatory factor, which produces short-chain fatty acids (SCFAs) can regulate host DNA methylation and is closely associated with a variety of metabolic diseases. The aim of this study is to elucidate the unique structure of enteric microbiota in PC, and explore the mechanism of "enteric microbiota-SCFAs-DNA methylation" pathway in the predisposition of PC to metabolic disorders. Various research techniques will be used in this study, such as 16S rRNA, GC-MS, and germ-free mice model. We will also validate the results from different aspects of the clinical phenomenon, in vitro and in vivo experiments. It will provide a new enteric microbiota approach to identify the PC, and lay a solid foundation for the early prevention of multiple metabolic diseases through the adjustment of PC enteric microbiota, which will profit the Chinese medicine clinical practice.

代谢疾病高发是当今亟待解决的全球性公共卫生问题，从中医痰湿体质入手可为代谢疾病的防治提供新的思路。中医学认为痰湿体质是多种代谢疾病发生的共同土壤，前期研究发现痰湿体质者在尚未罹患代谢疾病的情况下已经呈现出代谢紊乱性的DNA甲基化分子特征。然而关于痰湿体质出现代谢紊乱性DNA甲基化的作用机制，目前尚不明确。肠道菌群代谢产生短链脂肪酸（SCFAs）可调控宿主基因DNA甲基化，与多种代谢疾病密切相关。本研究旨在前期基础上，运用16S rRNA测序、GC-MS及无菌小鼠等多种技术，阐明痰湿体质独特的肠道菌群结构， 研究“肠道菌群-SCFAs-DNA甲基化”调控路径在痰湿体质代谢紊乱中的作用机制，并从临床现象、体外研究及体内研究不同层面进行验证。不仅从肠道菌群角度为痰湿体质体质微观辨识提供依据，并且为日后临床通过调节痰湿体质肠道菌群从而实现对于多种代谢疾病的早期防治奠定基础，助于实现中医“治未病”。

本项目在前期发现痰湿体质存在特异DNA甲基化特征的基础上，进一步从肠道菌群及其代谢物SCFAs的角度探索痰湿体质出现代谢紊乱相关DNA甲基化的作用机制。基于前期全基因组DNA甲基化基因芯片数据，本项目首先重新招募志愿者并采用焦磷酸测序的方法对前期筛选出的关键基因位点进行验证。其次，研究发现痰湿体质存在特异的肠道菌群结构，并且与代谢指标以及DNA甲基化水平密切相关。第三，进一步研究发现痰湿体质肠道菌群代谢产生SCFAs水平与平和体质存在显著差异，通过细胞体外实验以及FMT动物实验，证实SCFAs可对痰湿体质关键基因DNA甲基化进行调控，并且与糖脂代谢紊乱密切相关。本项目从肠道菌群SCFAs调控DNA甲基化的角度，阐释痰湿体质易发代谢性疾病的分子机制，为痰湿体质的微观筛查以及临床干预提供潜在靶点，具有重要意义。相关研究成果在SCI期刊Int J Mol Sci（IF=5.92）, Front Pharmacol（IF=5.81），Am J Chin Med（IF=4.67）以及T1级期刊《中华中医药杂志》等学术刊物发表论文8篇。项目负责人入选中华中医药学会“青年人才托举工程”项目A类人才，并获得教育部及中华中医药学会科研奖励2项。