PPARA and Reduced sperm motility: prausnitzii</i>-derived butyrate might impair Leydig cell steroidogenesis via disrupted PPAR signaling.<h4>Conclusions</h4>Asthenozoospermia is associated with gut dysbiosis characterized by loss of butyrate-producing bacteria, systemic and testicular disturbances in butyrate metabolism, and microbiota-mediated transmission of impaired sperm quality.