A review of urinary bladder microbiome in patients with bladder cancer and its implications in bladder pathogenesis

The recent discovery of the urinary microbiome has led to an emerging field of investigation about the potential role of microorganisms in the pathogenesis of urinary bladder cancer. Few preliminary data have been reported so far implicating urobiome as causative and prognostic factor of bladder tumorigenesis. In the present study, a review of the current evidence is presented about microbiome composition among patients with bladder cancer and healthy individuals as well as possible implications of microbiome on urothelial carcinoma of the bladder.

A literature review was conducted using PubMed/MEDLINE, Scopus, and the Cochrane library until December 2023. Search algorithm was constructed using the following terms and their associated Mesh terms and Boolean operators: "urinary microbiome" and "urinary microbiota". Studies written in English language, identifying, and comparing urinary microbiome among bladder cancer patients and healthy control group were included in the review.

A total of 2,356 reports were identified. From this total 16 articles complied with the inclusion criteria were selected for analysis. These articles represent a total of about 486 bladder cancer patients.

Recent studies revealed the colonization of the urinary tract and the bladder by micro-organisms using both enhanced culture- and molecular-based techniques for microbial characterization. However, several limitations exist in the literature decreasing the reliability of the current reports. As a result, urinary microbiome consist an ambitious era in bladder cancer research with an increasing number of evidence about its potential pathogenetic, prognostic and therapeutic role.