断奶应激易导致仔猪肠道损伤，导致养分消化吸收障碍并伴随着抵抗力下降和腹泻。在肠道诸多屏障中，人们更多关注仔猪肠道的化学屏障、生物屏障和免疫屏障，然而有较多的研究表明，肠道的物理屏障在养分吸收特别是脂肪酸吸收方面可能起着重要的作用，但肠道物理屏障的损伤对脂肪酸等养分的吸收的影响及其机制的研究鲜有报道。因此，本研究拟通过建立仔猪肠道物理屏障损伤模型，利用动物活体、组织和细胞试验，结合代谢组学、蛋白质组学以及同位素示踪法系统研究肠道物理屏障损伤对脂肪酸吸收的影响，并从肠道紧密连接蛋白、脂肪酸吸收转运关键蛋白及其信号通路进一步探索肠道物理屏障影响脂肪酸吸收的机制；在此基础上，探讨肠道物理屏障介导的抗菌肽对脂肪酸吸收的调控作用及其机制。这将为针对性的营养调控或防治仔猪因断奶应激造成的营养物质消化吸收障碍，提高仔猪养分利用效率，增强仔猪抗病力、降低断奶腹泻，减少抗生素的使用提供理论基础和技术支撑。

The gut barrier dysfunction caused by weaning stress in pigs，leads to impaired nutrient absorption, decreased immunity and even diarrhea. To date, most of researches have been focused on chemical, biological, and immunological barrier function in the intestinal tract. However, studies have shown that intestinal physical barrier may play an important role in the nutrients absorption, especially in fatty acid absorption. Till now, the effect of dysfunction in intestinal physical barrier on fatty acid absorption has been largely unknown. In this study, the dysfunction model of pig intestinal physical barrier will be established and the effect of physical barrier dysfunction on the absorption of fatty acid will be investigated in living animals, tissues and cells by using metabolomics, proteomics and isotopic tracer method. In addition, the molecular mechanism and signal pathway will be characterized by analyzing the effect of changes in intestinal tight junction proteins, fatty acid transporters on the fatty acid absorption. Furthermore, the experiments will be conducted to investigate the effect of antimicrobial peptide on the gut barrier function and intestinal fatty acid absorption as well as its underlying mechanism. The project will provide fundamental understanding and technical support for nutritional manipulation; to improve the nutrient utilization efficiency and disease resistant during weaning stress. It will further supply potential applications in reducing antibiotic usage and weaning diarrhea in piglets.