> Three randomized clinical trials showed that adult male circumcision significantly reduced the risk for HIV acquisition among heterosexual males by 51%–60% (95% confidence interval 16%–76%) over time. These trials also found that medically performed adult circumcision significantly reduced the risk of men acquiring two common sexually transmitted infections (STIs), including genital ulcer disease (GUD) prevalence by 47% and incidence by 48% and high-risk (i.e. oncogenic) types of human papilloma virus (HR-HPV) prevalence by 23%–47%.
It also seems to reduce the risk of UTIs
> Male circumcision has been shown to reduce the risk of urinary tract infections inmales aged 0–1 years by 90%, in males aged 1–16 years by 85%, and in males >16 years by 71%.
This data is from a report from the CDC https://stacks.cdc.gov/view/cdc/58456