Reinoso-Peláez Edgar L, Saura María, González Carmen, Ramón Manuel, Calvo Jorge H, Serrano Magdalena
Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Ctra. de La Coruña, Km 7.5, 28040, Madrid, Spain.
Universidad Politécnica de Madrid, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Madrid, Spain.
Microbiome. 2025 Aug 1;13(1):177. doi: 10.1186/s40168-025-02165-z.
Despite advancements in artificial insemination, sheep fertility rates remain suboptimal. Recent studies in other species highlight the critical role of reproductive microbiota in influencing fertility outcomes. This research explores the relationship between ovine vaginal microbiota, associated functional pathways, and fertility using advanced nanopore long-reading metagenomic sequencing on 297 ewes from three Spanish breeds across four herds. The study aimed to describe a core vaginal microbiota, analyse the complex interactions with herd, breed, age, and parity factors, and identify taxa and genes associated with reproductive success by artificial insemination.
The study identified Staphylococcus, Escherichia, and Histophilus as the most abundant genera. Microbial communities varied considerably between breeds and herds, with high predictive accuracy (> 90%) in classification models. Differential abundance analysis revealed that the genera Histophilus, Fusobacterium, Bacteroides, Campylobacter, Streptobacillus, Gemella, Peptoniphilus, Helococcus, Treponema, Tissierella, and Phocaeicola were more abundant in non-pregnant ewes. Some of these taxa were also associated with four COG entries and one KEGG orthologue significantly linked to non-pregnancy, primarily involving carbohydrate metabolism, defence mechanisms, and structural resilience. Age and parity were also associated with microbiota composition, particularly in ewes older than five years or with more than three parturitions, suggesting that cumulative physiological changes may contribute to microbial shifts over time.
The ewe's vaginal microbiome appears to be mainly influenced by both herd and breed, though distinguishing genetic from environmental factors is challenging within our study design. While the overall microbiota showed a subtle effect on pregnancy, certain genera had a significant negative impact, likely due to pathogenic or inflammatory properties that disrupt reproductive health. The metagenomic approach used here enabled not only comprehensive taxonomic classification but also detailed functional analysis, providing deeper insights into the microbiome's role in reproductive outcomes. Video Abstract.
尽管人工授精技术有所进步，但绵羊的繁殖率仍不尽人意。最近在其他物种中的研究凸显了生殖微生物群在影响繁殖结果方面的关键作用。本研究利用先进的纳米孔长读长宏基因组测序技术，对来自四个畜群的三个西班牙品种的297只母羊进行研究，探索绵羊阴道微生物群、相关功能途径与繁殖力之间的关系。该研究旨在描述核心阴道微生物群，分析与畜群、品种、年龄和胎次因素的复杂相互作用，并确定与人工授精繁殖成功相关的分类群和基因。
该研究确定葡萄球菌、大肠杆菌和嗜组织菌为最丰富的属。微生物群落因品种和畜群而异，在分类模型中具有较高的预测准确性（>90%）。差异丰度分析显示，嗜组织菌属、梭杆菌属、拟杆菌属、弯曲杆菌属、链杆菌属、孪生球菌属、消化球菌属、嗜球放线菌属、密螺旋体属、蒂氏菌属和福卡埃icola属在未怀孕母羊中更为丰富。其中一些分类群还与四个COG条目和一个与未怀孕显著相关的KEGG直系同源物相关，主要涉及碳水化合物代谢、防御机制和结构弹性。年龄和胎次也与微生物群组成有关，特别是在五岁以上或分娩三次以上的母羊中，这表明随着时间的推移，累积的生理变化可能导致微生物群落的变化。
母羊阴道微生物群似乎主要受畜群和品种的影响，尽管在我们的研究设计中区分遗传因素和环境因素具有挑战性。虽然整体微生物群对妊娠有微妙影响，但某些属有显著负面影响，可能是由于其致病或炎症特性破坏了生殖健康。这里使用的宏基因组方法不仅能够进行全面的分类学分类，还能进行详细的功能分析，为微生物群在生殖结果中的作用提供了更深入的见解。视频摘要。
