Probiotics and Male Fertility: The Research Behind Menceive

Male infertility accounts for around 50% of infertility cases.¹ While causes are multifactorial, ranging from genetics to lifestyle, emerging research points to the male reproductive microbiome as a significant factor influencing sperm health.^2–4 Menceive is formulated with specific probiotic strains to reduce inflammation and oxidative stress that impair sperm quality.^5,6

Understanding the Semen Microbiome

Semen was once believed to be sterile, but next-generation sequencing has shown it hosts a unique microbiota.^2–4 Disruptions in this microbial balance have been associated with:

• Subfertility and low semen quality^2–4
• Increased DNA fragmentation^2,3
• Impaired testicular function and inflammation^3,5

Lactobacillus-dominant semen samples show better sperm motility, viability, and morphology. These strains protect against lipid peroxidation and modulate inflammation.^3,4,7

How Probiotics Can Support Male Fertility

Inflammation in the male genital tract contributes to reduced semen quality via impaired gland function, oxidative stress, and microbial interference.^3,5 Probiotics with antioxidant and anti-inflammatory properties can support testicular function and protect sperm health through multiple mechanisms:^5,6

• Reducing inflammatory gut-derived bacteria^5,6
• Modulating immune function in the testes^5,6
• Improving hormone production and reproductive capacity^5,6

Clinical Findings on Menceive's Strains

Menceive contains Bifidobacterium longum ES1 CECT 7347 and Lactobacillus rhamnosus BPL15 CECT 8361. A study by Valcarce et al. evaluated these strains in men with low sperm motility (asthenozoospermia). The key findings after 21 days of supplementation included:

• Up to 6× improvement in sperm motility⁸
• Reduction in DNA fragmentation⁸
• Decrease in reactive oxygen species (ROS), indicating reduced oxidative stress⁸

Significant differences were observed in sperm quality in just one spermatogenic cycle (~3 weeks).⁹

This small study involved nine men with asthenozoospermia, so larger controlled trials are needed to confirm how consistently these findings apply in clinical practice.

Who Might Benefit

Menceive may be especially useful for individuals with:

• Low sperm motility⁸
• Elevated DNA fragmentation⁸
• Poor diet or lifestyle habits^1,5,6
• Inflammatory conditions of the male genital tract^3,5

While the semen microbiome is still being fully understood, early evidence shows that probiotics such as those in Menceive can offer measurable improvements in sperm motility, integrity, and reproductive performance—particularly through their anti-inflammatory and antioxidant effects.^5,6,8

References

1. Mayo Clinic. Male infertility: Symptoms and causes. Available from: https://www.mayoclinic.org/diseases-conditions/male-infertility/symptoms-causes/syc-20374773
2. Weng SL, Chiu CM, Lin FM, et al. The semen microbiome and its impact on sperm function and male fertility. Andrology. 2021;9(3):939–951. doi:10.1111/andr.12886.
3. Farahani L, et al. Semen Microbiome, Male Infertility, and Reproductive Health. Microorganisms. 2025;13(2):319. doi:10.3390/microorganisms13020319.
4. Štšepetova J, et al. Semen microbiota are dramatically altered in men with abnormal sperm parameters. Scientific Reports. 2024;14:1093. doi:10.1038/s41598-024-51686-4.
5. Chemes HE, Rawe VY. The role of oxidative stress in male infertility. Human Reproduction Update. 2010;16(3):271–291. doi:10.1093/humupd/dmp046.
6. Alfano M, Ferrarese R, Locatelli I, et al. The human microbiome and male infertility: A systematic review. Frontiers in Reproductive Health. 2023;5:1166201. doi:10.3389/frph.2023.1166201.
7. Is Lactobacillus spp. beneficial in human semen? A systematic review. Andrology. 2025. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC12469129/
8. Valcarce DG, Riesco MF, Martínez-Vázquez JM, Robles V. Probiotic administration improves sperm quality in asthenozoospermic human donors. Beneficial Microbes. 2017;8(2):193–206. doi:10.3920/BM2016.0122.
9. Valcarce DG, Riesco MF, Martínez-Vázquez JM, Robles V. Diet Supplemented with Antioxidant and Anti-Inflammatory Probiotics Improves Sperm Quality after Only One Spermatogenic Cycle in Zebrafish Model. Nutrients. 2019;11(4):843. doi:10.3390/nu11040843.