Investigations into the effects of antibiotics on the chicken gut microflora and development of gut-associated immune response

在饲料中亚治疗性使用抗生素是商业家禽生产中的一种常见做法，作为预防细菌感染和促进生长和生产的一种方式。然而，细菌中抗生素耐药性的发展正在成为动物和人类的共同问题。此外，抗生素治疗经常导致肠道微生物区系的不稳定，并可能对微生物区系与宿主之间的相互作用产生不利影响。许多食源性致病菌，如沙门氏菌和弯曲杆菌，都与禽肉、鸡蛋和其他产品有关。鸡的肠道微生物区系能够控制食源性病原体。因此，抗生素的不当使用不仅会影响动物健康，还会引发食品安全问题。这个项目研究肠道微生物区系和鸡免疫系统之间的相互作用。此外，它还试图确定这些效应的潜在细胞和分子机制。更具体地说，该建议将：1)研究饮食抗生素对肠道微生物区系组成的影响；2)研究微生物区系变化对肠道相关免疫系统的细胞和分子变化；3)调查微生物区系细菌结构成分刺激后肠道相关免疫系统的基因表达。这项拟议的计划有望提供对日粮抗生素对鸡免疫系统发育影响的分子/细胞机制的基本理解。此外，本研究将为鉴定微生物群落中存在的细菌的免疫调节属性奠定基础。

Subtherapeutic use of antibiotics in feed is a common practice in commercial poultry production as a way of prevention of bacterial infections and promoting growth and performance. However, the development of antibiotic resistance in bacteria is becoming a common issue in both animals and humans. In addition, antibiotic therapy often results in destabilization of gut microbiota and could adversely affect interactions between microbiota and the host. Many food-borne pathogens such as Salmonella and Campylobacter are associated with poultry meat, eggs and other products. The gut microbiota of chickens is capable of controlling food-borne pathogens. Therefore, inappropriate use of antibiotics not only affects animal health, but also raises food safety concerns. This program investigates interactions between the gut microbiota and the chicken immune system. Furthermore, it seeks to determine the underlying cellular and molecular mechanisms of these effects. More specifically, the proposal will: 1) examine the effects of dietary antibiotics on the composition of gut microbiota; 2) study cellular and molecular changes in the gut-associated immune system exerted by changes in the microbiota; 3) investigate gene expression in the gut-associated immune system following stimulation with structural components of microbiota bacteria. The proposed program is expected to provide fundamental understanding of the molecular/cellular mechanisms of dietary antibiotics effects on development of the chicken immune system. Furthermore, this research will lay the foundation for identification of immunomodulatory attributes of bacteria present in the microbiota community.