Exploring the Gut‐Prostate Axis: Microbial Signatures Linked to Prostate Volume and Bladder Function

BACKGROUND: Benign prostatic hyperplasia (BPH) is a common urologic condition in aging men, often linked to systemic inflammation and metabolic dysfunction. Emerging evidence suggests that the gut microbiome may contribute to prostate health and disease. Here we aim to explore potential associations between gut microbiota composition and clinical parameters, such as prostate volume (PV) and residual bladder volume (RBV). METHODS: This cross-sectional study analyzed stool samples from 28 patients undergoing transurethral surgery. Gut microbiota composition was analyzed using 16S rRNA gene sequencing. Patients were stratified into groups based on PV ( ≤ 40 mL vs. > 40 mL) and RBV ( ≤ 100 mL vs. > 100 mL). α-diversity (Chao1 and Shannon indices) and β-diversity (Jaccard distance) were calculated. Linear discriminant analysis effect size (LEfSe) was used to identify differentially abundant taxa between groups. RESULTS: No significant differences in gut microbial α- or β-diversity were observed between groups stratified by PV or RBV. Nevertheless, several specific bacterial taxa showed significant variation between groups. Methanobrevibacter smithii was markedly less abundant in patients with PV > 40 mL (p < 0.01). Similarly, patients with high RBV ( ≥ 100 mL) exhibited distinct gut microbial profiles compared to those with lower RBV, characterized by a reduced abundance of Collinsella and an increased abundance of Gastranaerophilales (both p < 0.01). CONCLUSION: Our findings suggest that while overall gut microbial diversity may remain stable, specific taxa are associated with prostate and bladder phenotypes, supporting the concept of a gut-prostate axis. Future research should focus on longitudinal studies to investigate how gut (and urinary) microbiota evolve alongside BPH and/or LUTS over time, with the goal of determining whether microbial signatures could serve as early indicators for symptomatic BPH.