Microbiome in Bladder Cancer: A Systematic Review.

Area of Science:

• Urology
• Microbiology
• Oncology

Background:

• The relationship between the human microbiome and bladder cancer is increasingly recognized.
• However, specific bacterial species influencing bladder cancer progression or risk have not been definitively identified.
• Existing research faces challenges including methodological heterogeneity in urine studies and limited species-level data from tissue and stool analyses.

Purpose of the Study:

• To systematically review and synthesize findings from all published microbiome studies related to bladder cancer.
• To identify specific bacterial species or consortia with potential roles in bladder cancer.
• To highlight limitations in current methodologies and suggest directions for future research.

Main Methods:

• A systematic literature search was conducted across major scientific databases.
• Studies investigating the microbiome in relation to bladder cancer (urine, tissue, stool) were included.
• Data on study design, methods, and identified microbial species were extracted and analyzed.

Main Results:

• Significant heterogeneity exists in methodologies employed across bladder cancer microbiome studies.
• Species-level identification of bacteria in urine and tissue samples remains largely unachieved.
• Stool microbiome studies offer some insights but provide limited direct relevance to bladder cancer.

Conclusions:

• Current evidence is insufficient to pinpoint specific bacterial strains at the species level crucial for bladder cancer.
• Standardization of methodologies in urine and tissue microbiome analysis is critical.
• Further targeted research is needed to elucidate the precise role of the microbiome in bladder cancer etiology and progression.