早期断奶技术易引起仔猪断奶应激综合征，导致断奶仔猪肠道黏膜免疫机能下降，继而发生肠毒素性大肠杆菌（ETEC）感染性肠道炎症和剧烈腹泻，给养猪业带来了巨大危害；由于肠道是机体最大的黏膜免疫屏障，亦是营养物质消化吸收的主要场所。因此，减轻或消除ETEC引起的断奶仔猪肠道炎症和黏膜损伤，维持肠道黏膜免疫屏障功能正常是保证仔猪健康生长的关键。本研究拟通过构建断奶仔猪体内外（猪肠道/肠上皮细胞）ETEC感染模型，观察猪肠道黏膜及肠上皮细胞免疫病理变化，结合流式细胞术、基因转录组测序技术、RNA干扰技术、免疫印迹技术、荧光定量PCR技术以研究TLR4-NF-kB、NOD1/2-RIP2-NF-kB/MAPK信号通路在ETEC诱导的猪肠道黏膜炎性损伤中的作用，评价香砂六君子汤及有效成分对ETEC诱导的仔猪肠道炎性损伤调控作用，确定ETEC感染引起断奶仔猪肠道黏膜炎性损伤的药物作用靶点及中药分子调控机制。

It is often happened to the weaned stress syndrome of piglets with the technology of early weaned piglets, which would cause the functions of intestinal mucosal immunity in disorder and fall in decline, and then the weaned piglets will be infected by Enterotoxigenic Escherichia coli (ETEC) with the severe intestinal inflammation and intestinal mucosal barrier damages. Therefore, it is the key to keep the weaned piglets in healthy by reducing or eliminating the intestine inflammation and damages caused by ETEC. The experiments will be carried out to investigate the pathological changes in the intestine gut and the intestinal epithelial cells injured with ETEC in vivo or vitro, and the effects of the TLR4-NF-kB and NOD1/2-RIP2-NF-kB/MAPK signal pathway on the intestine and intestinal epithelial cells infected with ETEC will be studied via Flow Cytometry, Gene transcriptome depth sequencing technology, RNA interference technology, western-blot, real-time PCR. And then, the results of experiments in vivo or vitro will be helpful to evaluate the regulatory mechanism of Xiangsha Liujunzi decoction and even the active ingredients, which will lead to determine the regulatory mechanism and targets of the injury of ETEC to intestinal mucosal immunity in weaned piglets.