Herzog Fiona, Crissman Kassandra R, Beckers Kalie F, Zhou Guoli, Liu Chin-Chi, Sones Jenny L
Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA.
Center for Statistical Training & Consulting (CSTAT), Michigan State University, East Lansing, MI 48824, USA.
Vet Sci. 2025 Mar 3;12(3):232. doi: 10.3390/vetsci12030232.
Dysbiosis of the lower reproductive tract (LRT) in mares may play a role in clinical diseases, including endometritis and placentitis. Metagenomic/metagenetic analysis of bacterial DNA can identify organisms that are not readily cultured and, thus, may go undetected. In this study, we tested the following hypotheses: (1) the clitoris of estrual mares harbors a unique resident microbiome, (2) topical Lactobacillus genus complex (LGC)-containing probiotic will alter the equine clitoral microbiome, and (3) early pregnancy rates following clitoral LGC application will not differ significantly from industry standards. Mares (n = 12) in estrus had sterile clitoral swabs collected (0) prior to daily topical LGC for 4 days. Second (12 h) and third clitoral swabs (48 h) were collected following final LGC application. During the next estrus, the mares were bred by artificial insemination. Genomic DNA was extracted and used for 16S rRNA sequencing via the Illumina Miseq platform. Abundance was evaluated via Friedman test with pairwise Dunn's post hoc comparisons. Statistical significance was set at < 0.05. Compared to time 0, Desulfobacterota decreased and spp. increased at 12 h and 48 h compared to 0, while and spp. increased in a time-dependent manner. Furthermore, spp. and Christensenellacea_R-7_group decreased at 12 h and 48 h compared to 0. LGC changed the beta but not alpha diversity at both 12 h and 48 h. Mares with LGC application achieved an 85% pregnancy rate in the subsequent estrus. Future investigations are needed to understand the role of the LRT microbiome and probiotics in equine breeding.
母马下生殖道（LRT）的微生物失调可能在包括子宫内膜炎和胎盘炎在内的临床疾病中起作用。对细菌DNA进行宏基因组/宏基因分析可以识别不易培养的微生物，因此可能未被检测到。在本研究中，我们检验了以下假设：（1）处于发情期的母马阴蒂中存在独特的常驻微生物群；（2）局部应用含乳酸杆菌属复合体（LGC）的益生菌会改变马的阴蒂微生物群；（3）阴蒂应用LGC后的早期妊娠率与行业标准相比无显著差异。处于发情期的母马（n = 12）在每日局部应用LGC 4天之前采集无菌阴蒂拭子（0时）。在最后一次应用LGC后采集第二次（12小时）和第三次阴蒂拭子（48小时）。在下一个发情期，通过人工授精使母马受孕。提取基因组DNA，并通过Illumina Miseq平台用于16S rRNA测序。通过Friedman检验及两两比较的Dunn事后检验评估丰度。设定统计学显著性为<0.05。与0时相比，脱硫杆菌门在12小时和48小时减少，而某些菌属增加，同时某些菌属和某些菌属以时间依赖性方式增加。此外，与0时相比，某些菌属和克里斯滕森菌科R-7组在12小时和48小时减少。LGC在12小时和48小时均改变了β多样性，但未改变α多样性。应用LGC的母马在下一个发情期的妊娠率达到85%。未来需要进行研究以了解LRT微生物群和益生菌在马繁殖中的作用。
