Is Lactobacillus spp. beneficial in human semen? Systematic review

The present systematic review aimed to evaluate the effects of Lactobacillus spp. on human semen. The review was conducted until May 2023, according to the PRISMA Statement and using Scopus and PubMed databases. The protocol was registered on PROSPERO (CRD42024519245). All published original investigation peer-reviewed articles in English and Spanish related to Lactobacillus spp. and human semen parameters were eligible. The quality assessment used The Joanna Briggs Institute (JBI) Critical Appraisal Checklist and QUIN tool. In total, 35 articles were included. Lactobacillus spp. is frequently detected in semen, and its impact on seminal quality is controversial, especially regarding the methodology used. The intake of probiotics with Lactobacillus spp. can improve semen parameters. In conclusion, Lactobacillus spp. appears to have a beneficial role in semen quality. Probiotics could have a good impact on improving semen quality; however, further studies are required.