Dysbiosis in Human Urinary Microbiota May Differentiate Patients with a Bladder Cancer

Abstract

Recent interest in noninvasive diagnostic approaches has highlighted the potential of urinary microbiota as a novel biomarker for bladder cancer. This study investigated the urinary microbiota of 30 bladder cancer patients and 32 healthy controls using a specific NGS protocol that sequences eight hypervariable regions of the 16S rRNA gene, providing detailed insights into urinary microbiota composition. The relative abundance of microbial compositions in urine samples from cancer patients and healthy controls was analyzed across various taxonomic levels. No notable differences were highlighted at the phylum, class, order, and family levels. At the genus level, 53% of detected genera were represented in either cancer patients or healthy controls. Microbial diversity was significantly lower in cancer patients. The differential analysis identified five genera, Rhodanobacter, Cutibacterium, Alloscardovia, Moryella, and Anaeroglobus, that were significantly more abundant in cancer patients. Notably, Rhodanobacter was present in 20 cancer samples but absent in healthy controls. Conversely, 40 genera, including Lactobacillus, Propionibacterium, and Bifidobacterium, exhibited reduced abundance in cancer patients. These findings suggest that some genera may serve as potential biomarkers for bladder cancer, highlighting the need for further research to explore their roles in disease pathogenesis and their potential applications in diagnostics and therapeutics.

Keywords: Cutibacterium; NGS; Rhodanobacter; bladder cancer; urinary microbiota.

Figure 1

Average relative abundance of microbial taxa in urine samples from bladder cancer patients and healthy volunteers. Taxa with a relative abundance of <1% are grouped under “Others”. The percent community composition is shown at the phylum (A), class (B), order (C), family (D), and genus (E) levels. NA, non-attributed operational taxonomic units (OTUs).

Figure 2

Urinary microbiota composition of samples at the genus level. (A) Relative abundance of microbial taxa in individual urine samples from bladder cancer patients and healthy volunteers. Taxa with a relative abundance of <1% are grouped under “Others”. (B) Shannon diversity index of urine samples from bladder cancer patients and healthy volunteers. Box plots display the median and range of diversity measures.

Figure 3

Differential urinary microbiota abundance profiles between bladder cancer patients and healthy volunteers. (A) Cladogram showing the differentially represented taxa across taxonomic ranks. Each circle corresponds to a taxonomic level; from the center outward: phylum, class, order, family, and genus. Blue dots indicate taxa underrepresented in the urine samples of bladder cancer patients; red dots indicate taxa that are overrepresented. Grey dots represent taxa detected in both groups without significant differences. (B) Dot plot illustrating the genera with significant differential representation between the two groups. Genera are considered significant if their |log2 fold change| is ≥1 and the p-value ≤ 0.05.