KLK3 and periodontitis: Previous studies found a relationship between periodontitis and prostatitis [28,29], specifically in moderate-severe periodontitis, due to greater probing depths (LAC), worse plaque index (PI) values and worse bleeding rates, and higher prostate-specific antigen (PSA) levels (≥4 ng/mL), possibly due to oral microbiome biotypes (Treponema denticola, P. gingivalis and Tanarella forsythea).