The Urinary Microbiome in Bladder Cancer Patients - Expert Commentary

The link between the urinary microbiome and bladder carcinogenesis is not well understood. A recent study published by Chipollini et al. in Urologic Oncology profiled the microbial communities in the urine of bladder cancer patients and non-cancer participants.


The authors performed 16S ribosomal RNA sequencing on bacteria isolated from urine samples. They compared the heterogeneity in the microbiome between bladder cancer patients and non-cancer participants. The study included 37 samples with adequate sequencing data for analysis. These included 10 non-cancer samples, 15 samples from muscle-invasive urothelial carcinoma (UC) samples, and 12 patients with non-muscle invasive. UC. The authors analyzed the alpha and beta diversity of the microbiomes in each group.

The non-cancer group had higher species evenness than the muscle-invasive cancer group (P = 0.031) and nonmuscle-invasive UC group (P = 0.002). Similarly, the phylogenetic diversity was significantly higher in the control group compared to the muscle-invasive (P = 0.007) and nonmuscle-invasive UC samples (P < 0.001). On the other hand, there was no significant difference in pairwise comparisons when they evaluated beta diversity. The authors found that Bacteroides, Lachnoclostridium, and Burkholderiaceae were significantly found in non-cancer samples, while invasive cancer samples were enriched with Bacteroides and Faecalbacterium. There were no significantly enriched taxa found in nonmuscle-invasive UC samples.

This study highlights the differences in the diversity of microbiomes in patients with bladder cancer. Understanding how the urinary microbiome evolves following therapeutic interventions and whether these changes impact response are critical active areas of research. 

Written by: Bishoy M. Faltas, MD, Director of Bladder Cancer Research, Englander Institute for Precision Medicine, Weill Cornell Medicine, New York City, New York

Reference:

  1. Chipollini, Juan, Justin R. Wright, Hephzibah Nwanosike, Carole Y. Kepler, Ken Batai, Benjamin R. Lee, Philippe E. Spiess, David B. Stewart, and Regina Lamendella. "Characterization of urinary microbiome in patients with bladder cancer: Results from a single-institution, feasibility study." In Urologic Oncology: Seminars and Original Investigations. Elsevier, 2020.
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