Probiotic supplementation in men with asthenozoospermia: A randomized controlled trial

Objective: To investigate the potential of oral probiotics to improve sperm motility and decrease DNA fragmentation in men diagnosed with asthenozoospermia. Methods: Men diagnosed with asthenozoospermia, aged between 18 and 40 years, were randomly assigned to receive probiotic or placebo for 10 weeks. Sperm parameters (count, motility, and morphology) and seminal fluid biochemical markers were assessed using light microscopy and Diff-Quik staining. Intracellular reactive oxygen species levels were measured using the malondialdehyde (MDA) technique, while DNA fragmentation index (DFI) was evaluated through acidic aniline blue staining. Data from both groups were compared to determine the effects of probiotic supplementation. Results: Sixteen men were included. The probiotic group ( n =8) showed a significant increase in total sperm motility ( P <0.001) and progressive motility ( P =0.003) compared to the placebo group ( n =8). Additionally, sperm count in the probiotic group was significantly higher than in the placebo group, although other sperm parameters did not show significant changes. Notably, levels of MDA ( P =0.027) and DFI ( P =0.004) were significantly reduced in the probiotic group, indicating a decrease in oxidative stress and DNA damage. Conclusions: Probiotic supplementation effectively enhances sperm quality by mitigating oxidative stress and reducing DNA damage, thereby improving sperm motility in men with asthenozoospermia. Study registration: The trial was registered with the Iranian Registry of Clinical Trials (IRCT20220119053769N1).