A causal link was observed between male infertility and Lactococcus (OR = 1.05, 95% CI = 1.00–1.11, P = .048) and between SPAG11B and Coprococcus 2 (β = 0.08, 95% CI = 0.01–0.14, P = .02) but not with other gut microbiota genera. Here, SPAG11B is linked to male infertility.