Idiopathic male infertility is characterized by increased mortality or reduced motility and vitality of sperm. There are several reports on probiotics in the male reproductive tract, but the effects of these probiotics on sperm motility remain to be elucidated. In this study, we investigated the impact and mechanism of probiotics on the vitality and motility of mouse sperm. We collected mature sperm from the caudal vas deferens of mice and prepared three probiotics donated by HEM Pharma Inc.: Lacticaseibacillus rhamnosus, Limosilactobacillus fermentum, and Lacticaseibacillus paracasei. We analyzed the vitality and motility of sperm according to the concentration and duration of probiotic treatment. The probiotics increased the motility and vitality of sperm. Specifically, they enhanced sperm motility by 30-40% compared with untreated sperms. The probiotics enhanced mitochondrial activity in sperm through specific factors like AMPK and SIRT1. All three probiotics enhanced the activities of mitochondrial function-related proteins in sperm. In conclusion, we found that the probiotics improved the vitality and motility of mouse sperm and increased mitochondrial function in mature sperm. These findings suggest that probiotics can be utilized to enhance sperm motility and treat male infertility.
Keywords: mitochondrial activity; motility; probiotics; spermatozoa; viability.