Lactobacillus Genus Complex Probiotic-Induced Changes on the Equine Clitoral Microbiome

Area of Science:

• Equine reproductive microbiology
• Microbiome analysis
• Probiotic applications in animal health

Background:

• Lower reproductive tract (LRT) dysbiosis in mares is linked to endometritis and placentitis.
• Metagenomic analysis detects unculturable bacteria, offering deeper insights into the microbiome.
• The clitoral microbiome's role in equine reproductive health requires further investigation.

Purpose of the Study:

• To determine if the estrual mare clitoris harbors a unique microbiome.
• To assess the impact of a Lactobacillus genus complex (LGC)-containing probiotic on the equine clitoral microbiome.
• To evaluate if clitoral LGC application affects early pregnancy rates compared to industry standards.

Main Methods:

• Sterile clitoral swabs were collected from 12 mares in estrus before and after daily topical LGC application.
• 16S rRNA sequencing on the Illumina Miseq platform was used to analyze bacterial DNA.
• Bacterial abundance and diversity were statistically evaluated, with significance set at p < 0.05.

Main Results:

• LGC application altered bacterial populations, decreasing Desulfobacterota and increasing Corynebacterium spp.
• Actinobacillus and Fusobacterium spp. showed time-dependent increases, while Mobiluncus spp. and Christensenellacea_R-7_group decreased.
• LGC significantly changed beta diversity but not alpha diversity of the clitoral microbiome.

Conclusions:

• The equine clitoral microbiome composition is altered by topical LGC application.
• The study achieved an 85% pregnancy rate in mares treated with LGC, meeting industry standards.
• Further research is needed to elucidate the role of LRT microbiome and probiotics in equine breeding success.