The association of the prostate microbiome with pathologies

Introduction and ObjectiveThe etiology of benign prostatic hyperplasia (BPH) is not well understood, though it has been associated with age and inflammation. Recent literature has associated the urinary tract microbiome with various urologic diseases such as lower urinary tract symptom severity to specific microbiota. We aimed to examine the prostatic microbiome in BPH and associations with patient characteristics.MethodsMen undergoing Holmium Laser Enucleation of the Prostate (HoLEP) for BPH were recruited if they were over 18 years old, had no history of prostate cancer or surgery, or prior pelvic radiation. Patients were excluded if they had a positive preoperative urine culture, bladder stones, or were catheter-dependent. Patient characteristics including age, prostate specific antigen (PSA), American Urological Association symptom score (AUASS), and history of biopsy were recorded. Intraoperatively, prostate tissue was collected from each patient, as well as catheterized urine, urethral swabs, and swabs of the specimen container for negative controls. Samples underwent DNA extraction, 16S sequencing, and analysis using R statistical software. Associations between bacterial taxonomic diversity (alpha, beta, taxonomy) and patient characteristics were quantified through Sparcc correlations.Results50 patients were recruited for this study. Mean age, PSA, prostate size, and AUASS were 67.8 years, 4.0 ng/mL, 108.6 g, and 19.4, respectively. After bioinformatic decontamination of prostate samples, alpha and beta diversity analyses indicated that microbiomes from the prostate, urethra, and urine were all distinct (p=0.001), with the urine and urethra having higher similarity to each other than to the prostate. Campylobacter, Caryophanaceae, Enterobacter, and Senegalimassilia positively correlated with prostate size or PSA. History of prostate biopsy and AUASS did not significantly associate with specific bacteria.ConclusionsThis study represents the most robust examination of the prostatic microbiome in BPH, and the first to correct for possible contaminants while using prostate tissue. We observed a unique prostatic microbiome distinct from that of the urine and urethra, with several known pathogens positively correlated with prostate size and PSA.