槲皮素调控大肠杆菌感染SPF鸡的分子机制

槲皮素是多种天然植物的主要成分，替代饲用抗生素潜力巨大，但其在鸡体内是以原型还是其代谢产物调节机体代谢？能否替代饲用抗生素应用于养鸡生产预防鸡大肠杆菌病发生等问题限制了槲皮素在养鸡生产中的应用。本课题组前期研究表明，饲料适量添加槲皮素可促进正常蛋鸡和肉鸡肠道有益菌生长，抑制肠道有害菌生长，也能提高肉鸡免疫功能，但具体作用机制仍不清楚。. 本研究基于“槲皮素—体内代谢和调控—实际应用”这一思路，SPF鸡饲喂含槲皮素饲粮2周后用大肠杆菌感染，采用代谢组学LC-MS、宏基因组和16S rDNA测序等方法探讨槲皮素在体内的代谢、如何调节回肠微生态和/或机体免疫功能，从而降低SPF鸡大肠杆菌感染的发病率和死亡率。本研究可以突破天然植物有效成分在畜牧生产中应用的瓶颈，在饲用抗生素替代品研发方面形成我国在天然植物饲料添加剂领域的优势，符合当前“禁抗”的健康养殖概念，应用前景广阔。

As an important ingredient from various kinds of plant, quercetin has shown a great potential in feeding antibiotic alternatives, however, some problems hindered application of quercetin in chicken production, such as how to work and supplement, dosage, whether or not substitute feeding antibiotics, etc. Previous results in our laboratory have shown that quercetin promoted growth of beneficial bacteria and inhibited growth of harmful bacteria in normal laying hens and broilers; Meanwhile, quercetin improved immunity in healthy broilers. However, the mechanism of action is still unclear..The present project based on the idea of “quercetin-metabolism and regulation-application”. SPF chickens were challenged with E coli after SPF chickens were fed by diet supplemented with quercetin for 2 weeks. This project will investigate metabolism of quercetin, regulation of flora in ileum and/or immunity of SPF chickens using LC-MS, metagenome and 16S rDNA sequencing techniques, etc, thereby decrease morbidity and mortality in SPF chickens challenged with E coli. This study will break through the bottlenecks in application of effective components from natural plant in livestock production. We will form the advantage of feeding antibiotic alternatives in the field of feed additive from natural plant. The project is accordant with healthy livestock farming concept of “prohibition of antibiotics”, has broad prospects of application.