The Semen Microbiome and Semen Parameters in Healthy Stallions.
Authors: Quiñones-Pérez Carlota, Martínez Amparo, Ortiz Isabel, Crespo Francisco, Vega-Pla José Luis
Journal: Animals : an open access journal from MDPI
Summary
# The Semen Microbiome and Semen Parameters in Healthy Stallions — Editorial Summary Whilst advances in equine reproductive technology continue apace, a significant proportion of stallions present with unexplained poor semen quality, and the underlying causes remain poorly characterised. Drawing on evidence from human reproductive medicine where specific bacterial families have been linked to idiopathic infertility, Quiñones-Pérez and colleagues investigated whether seminal microbiota composition correlates with key sperm quality indicators—including concentration, total sperm number, motility (both total and progressive), and DNA fragmentation—in healthy stallions using 16S rRNA sequencing to identify bacterial families present at >1% relative abundance. Their analysis revealed a modest but potentially significant microbial influence on spermatozoa function: Peptoniphilaceae demonstrated a positive correlation with total sperm motility, whilst Clostridiales Incertae Sedis XI showed a negative association with progressive motility, though notably no other bacterial families showed meaningful relationships with the measured parameters. These findings suggest that seminal microflora may play a regulatory role in spermatozoon activity, though the mechanisms of interaction remain speculative and warrant further mechanistic investigation; for practitioners managing subfertile stallions, this work indicates that microbiological assessment of semen samples could eventually form part of a comprehensive diagnostic approach, though current evidence remains correlative rather than causative.
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Practical Takeaways
- •Seminal microbiota composition should be considered as a potential contributing factor in stallions with unexplained low sperm quality or reduced motility
- •Microbiological assessment via 16S rRNA sequencing may help identify bacterial profiles associated with poor semen parameters in breeding soundness evaluations
- •Further research is needed before microbiome-targeted interventions can be recommended for managing stallion subfertility
Key Findings
- •Peptoniphilaceae family showed positive correlation with total sperm motility in stallion ejaculates
- •Clostridiales Incertae Sedis XI family showed negative correlation with progressive motility
- •Only 2 of multiple bacterial families examined demonstrated significant associations with sperm quality parameters
- •Seminal microbiome composition may influence spermatozoa activity in stallions