近日，华中农业大学农业微生物资源发掘与利用全国重点实验室、教育部动物育种与健康养殖前沿科学中心、湖北洪山实验室、动物科学技术学院、动物医学院孙铝辉教授团队以“Duodenal resident Limosilactobacillus improves feed efficiency through ornithine-mediated optimization of gut microbiota and nutrient absorption via the Nrf2 signaling”为题在Microbiome期刊上发表最新研究成果。该研究以肉鸡为研究对象，发掘出功能微生物菌株嗉囊粘液乳杆菌CC32 （L . ingluviei CC32）和阴道粘液乳杆菌LD11 （L . vaginalis LD11），并阐明其通过产生鸟氨酸调节十二指肠微生物群和提高营养吸收能力的作用机制，在实施肠道菌群和代谢物干预改善肉鸡肠道健康和提高饲料利用效率具有重要意义。
肉鸡产业为人类营养提供优质蛋白来源。我国饲料资源短缺，人畜争粮等问题日益严重，提高肉鸡饲料利用效率成为实现肉鸡高效养殖和保障鸡肉相关产品稳定供给的重要途径。肠道微生物组是影响家禽健康的重要因素，与盲肠发酵功能不同，鸡十二指肠具有快速转运和高酶活性的特点，其微生物群参与调节肠腔营养物质的消化吸收，直接影响肠上皮功能和营养物质转运蛋白的活性。然而，与肉鸡高饲料利用效率相关的十二指肠微生物群的功能特征，以及其促进养分利用的机制尚不清楚。
研究人员通过构建高低饲料利用效率肉鸡模型，发掘能显著提高饲料利用效率的关键肠道菌群，并体外分离纯培养候选菌株，解析了其与宿主互作的分子机制。结果显示，高饲料利用效率的肉鸡十二指肠微生物群落具有更强的相互合作性，其中粘液乳杆菌属，尤其是L . ingluviei CC32和L . vaginalis LD11菌株，通过产生鸟氨酸重塑十二指肠微生物群，并通过激活Nrf2信号促进肉鸡十二指肠抗氧化能力和营养物质转运，提高饲料利用效率。研究结果促进了对肉鸡十二指肠微生物功能作用的理解，为通过靶向肠道菌群创制新型营养调控技术改善肉鸡肠道健康，进一步提升其饲料利用效率提供了新的思路。华中农业大学动物科学技术学院、动物医学院博士后邓章超为论文第一作者，孙铝辉教授为通讯作者。加拿大英属哥伦比亚大学Leluo Guan教授提供了重要指导，博士后黄宇轩、赵玲，博士生曹可欣，硕士生彭哲、Alainaa Refaie，埃及本哈大学Mahmoud Mohamed Khalil博士也参与了该研究。研究得到了国家自然科学基金国际合作与交流项目、国家重点研发计划项目等项目的资助。
【英文摘要】
Background
The small intestinal microbiota directly influences host intestinal digestive and absorptive responses to dietary nutrients and plays a crucial role in optimizing feed efficiency in food-producing animals. However, the microbial functions of small intestine in regulating feed efficiency in broiler chickens remain to be elucidated.
Methods
A total of 150 healthy broilers were individually housed under identical feeding conditions to accurately calculate their feed efficiency. The gut microbiota in different intestinal segments of high and low feed efficiency chickens were compared using 16S rRNA sequencing. Gut bacterial candidates associated with feed efficiency were identified through a two-part model, LEfSe, and the Wilcoxon rank-sum test. Another 1725 1-day-old male broiler chicks were fed either a basal diet （BD） or BD supplemented with four different bacterial candidates isolated from the chicken gut to investigate their roles in regulating gut microbiota and nutrient absorption. The underlying molecular mechanisms by which key Limosilactobacillus strains and their metabolite ornithine improve intestinal health were also examined using an intestinal epithelial cell line.
Results
This study found that chickens with high feed efficiency exhibited greater microbial community stability and stronger cooperative interactions compared to low feed efficiency chickens, particularly within the duodenal microbiota. Meanwhile, duodenal resident Limosilactobacillus were significantly positively correlated with feed efficiency. Further validation trials revealed that specific Limosilactobacillus strains （L. vaginalis LD11 and L. ingluviei CC32） significantly improved feed efficiency, concurrently enhancing antioxidant capacity, barrier function, nutrient absorption, as well as increasing Limosilactobacillus abundance in the duodenum. These two bacterial strains could produce high concentrations of ornithine in the duodenum, which effectively alleviated LPS-induced intestinal cell damage by enhancing antioxidant capacity and upregulating the protein expression of nutrient transporters. Mechanistically, both bacterial strains and ornithine enhanced antioxidant capacity and nutrient uptake by activating Nrf2 signaling.
Conclusions
Dietary intervention using L. vaginalis LD11 and L. ingluviei CC32 contributes to high feed efficiency by producing ornithine, which modulates the duodenal microbiota and enhances the intestinal physiological functions for nutrient absorption
论文链接：https://link.springer.com/article/10.1186/s40168-026-02461-2
日期：2026-08-07
