Urinary microbiota in patients with prostate cancer and benign prostatic hyperplasia

INTRODUCTION Inflammation is associated with promotion of the initiation of various malignancies, partly due to bacterial infection-induced microenvironmental changes. However, the exact association between microbiota in urine, seminal fluid and the expressed prostatic secretions and benign prostatic hypertrophy and prostate cancer is not clear. MATERIAL AND METHODS In the present study, we investigated the type of microbiota in the expressed prostatic secretions (EPS) of patients with prostate cancer and benign prostatic hyperplasia (BPH) by the polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method using universal bacterial primers. In order to understand the possible association between various bacteria and prostate cancer, quantitative real-time PCR assay was performed to quantify the amount of strains of bacteria in urine, EPS and seminal fluid. RESULTS The prostate cancer group had a significantly increased number of Bacteroidetes bacteria, Alphaproteobacteria, Firmicutes bacteria, Lachnospiraceae, Propionicimonas, Sphingomonas, and Ochrobactrum, and a decrease in Eubacterium and Defluviicoccus compared to the BPH group. The number of Escherichia coli in the prostate cancer group was significantly decreased in urine and increased in the EPS and seminal fluid, while the number of Enterococcus was significantly increased in the seminal fluid with little change in urine and EPS. CONCLUSIONS Based on these results, we suggest that there are significant changes in the microbial population in EPS, urine and seminal fluid of subjects with prostate cancer and BPH, indicating a possible role for these bacteria in these two conditions.