新生羔羊分泌型IgA驱动肠道微生物定植机理及初乳调控

初乳是动物出生后的第一“餐”，大量微生物随初乳进入体内，新生羔羊肠道微生物定植过程中如何特异性保留共生菌定植并清除有害菌的机制尚不清楚。本项目以山羊为试验动物，围绕新生羔羊宿主分泌型IgA（sIgA）驱动肠道微生物定植机理和初乳调控这一科学问题，首先利用流式分选或磁珠富集技术构建山羊IgA共生菌群的研究方法，之后运用构建方法研究乳饲喂量和饲喂时间对新生羔羊sIgA共生菌群的影响，同时利用电镜、酶联免疫、功能基因组等实验技术检测不同初乳营养条件下新生羔羊肠道微生物定植和宿主代谢应答等情况，旨在阐明新生羔羊肠道sIgA与微生物定植互作关系，解析羔羊肠道微生物定植宿主调控靶点，并揭示初乳影响新生羔羊肠道微生物定植的宿主选择性机制。项目的实施将极大丰富和发展羔羊肠道微生物定植与宿主互作方面的理论，为制定新生羔羊优化培育措施，进而改善其生长发育和健康状况提供新的研究思路、研究方法和理论基础。

Colostrum is the first "meal" of goats after birth, and many microorganisms enter the gut following with colostrum ingestion. However, the mechanisms how the gut mucosa could specifically retain symbiotic bacteria colonization and remove harmful bacteria in gut of neonatal goats are unclear. In order to study the mechanism how gut microbial colonization in neonatal goats is driven by secretory immunoglobulin A (sIgA) during colostrum feeding, approaches of using flow cytometry or immuno-affinity benchtop to separate and identify the IgA specific symbiotic bacteria will be developed firstly. Then, two animal experiments will be conducted to investigate the effects of amount and feeding time of colostrum on the gut microbial colonization driven by secreted IgA using functional genomics analysis, electron microscopy, enzyme-linked immunosorbent assay, and the established flow cytometry or immuno-affinity benchtop method. This project will be helpful to elucidate the mechanism how the gut microbial colonization driven by sIgA, to identify the targets regulating gut microbial colonization, and to uncover the host selection mechanisms for gut microbial colonization affected by colostrum feeding in neonatal goats. The implementation of this project will greatly enrich and develop the theory of gut microbial colonization and host interaction in goats, and provide new research ideas, research methods and a theoretical basis for formulating feeding strategies to improve neonatal growth and health in goats.