基于肠道微生态的变化探讨湿热证的生物学基础及相关方剂的作用机制

湿热证是临床常见证型之一，以大便粘滞、臭秽，身热不扬，头重如裹，疾病缠绵难愈，脉滑数、苔黄腻等为主要临床特点。本团队既往发现湿热会导致肠道菌群结构和功能失调，继而下调机体天然免疫识别与应答，改变单胺类神经递质的表达等；但未对肠道菌群具体定量，也未对肠黏膜免疫及脑肠互动做系统研究。基于前期基础，提出科学假说：湿热证所引起的大便臭秽等症状可能由肠道微生物及其代谢产物失衡，肠道通透性增加所致，其结果进一步引起肠黏膜免疫及脑肠轴紊乱，从而导致了湿热证的头重如裹、身热不扬、病情缠绵难愈等。为阐明该问题，本项目拟采用宏基因组测序分别对湿热证流感小鼠及患者的肠道微生物定性定量，使用蛋白组和代谢组学等方法探讨其肠屏障、肠黏膜免疫、脑肠互动相关神经递质等变化，并通过Nod2-/-，Btk-/-基因敲除小鼠验证其具体靶点，同时采用湿温初起经方藿朴夏苓汤加以验证，依此揭示湿热证的生物学基础及相关方剂的作用机制。

As one of the most common syndromes in clinical syndrome types of TCM, damp-heat syndrome has these typical symptoms, such as sticky and fetid stool, hiding fever, head with binding sensation, slippery and rapid pulse, yellow greasy fur, with diseases lingering and refractory. Our previous studies found that alteration of intestinal flora could down-regulate the recognition and response of host natural immunity, and also had effect on the expression of the monoamine neurotransmitter.However, more research is needed on the specific quantitative measurement of intestinal flora, as well as the relationship among intestinal mucosal immunity, brain intestinal interaction and intestinal microecology. Based on previous research work, some scientific hypotheses are put forward: The changes of stool character in damp-heat syndrome may attribute to the alteration of intestinal flora , the imbalance of specific metabolite and the hyperpermeability of intestinal, and then they would cause the dysfunction of intestinal mucosal immunity and brain-gut axis, which ultimately lead to the typical symptoms of damp-heat syndrome. In order to reveal the biological basis of damp-heat syndrome and the pharmacological mechanism of related prescriptions, qualitative and quantitative analysis of human and mice intestinal flora is made by metagenome sequencing while proteomics and metabolomics are used to measure the changes of intestinal barrier, intestinal mucosal immunity, neurotransmitter and other related indexes. Besides, mice with Btk or Nod2 gene knockout are used to explore the effect targets, while decoction huo pu xia ling tang plays the role of verification.