Gut microbiota and male fertility: A two-sample Mendelian randomization study

Area of Science:

• Microbiology
• Genetics
• Reproductive Health

Background:

• Alterations in gut microbiota composition are linked to male fertility.
• Establishing a causal relationship between gut microbiota and male fertility remains challenging.

Purpose of the Study:

• To evaluate the causal effect of gut microbiota on male fertility using Mendelian randomization (MR).
• To identify specific bacterial taxa causally associated with male infertility, abnormal spermatozoa, and erectile dysfunction.

Main Methods:

• Genome-wide association study (GWAS) summary statistics for 211 gut bacterial taxa and male fertility traits were analyzed.
• Two-sample MR analysis, including IVW, weighted median, MR-Egger, and MR-PRESSO methods, was employed.
• Sensitivity analyses (Cochran's Q test, MR-Egger intercept, leave-one-out, funnel plot) were conducted to ensure result robustness.

Main Results:

• A causal relationship was identified between three bacterial genera and male fertility.
• Decreased Ruminiclostridm6 abundance was associated with increased risk of male infertility (OR=0.537).
• Reduced Prevotella9 was linked to abnormal sperm (OR=0.670), and Lachnospiraceae NC2004 group was associated with erectile dysfunction (OR=1.173).

Conclusions:

• The study suggests a causal role for Ruminiclostridm6, Prevotella9, and Lachnospiraceae NC2004 group in male fertility.
• These findings offer novel insights into gut microbiota-mediated mechanisms affecting male reproductive health.
• Further research is needed to elucidate the specific mechanisms underlying the role of these bacteria.