# Fecal microbiota transplantation: a novel strategy and challenges in the adjuvant treatment of bladder Cancer

## TL;DR

This review explores fecal microbiota transplantation (FMT) as a potential new adjuvant treatment for bladder cancer, focusing on its role in improving therapy effectiveness and addressing challenges in clinical management.

## Contribution

The paper systematically reviews the potential of FMT as an innovative adjuvant strategy for bladder cancer treatment.

## Key findings

- Gut microbiota dysbiosis is linked to bladder cancer progression and treatment response.
- FMT may enhance therapy effectiveness by modulating microbial metabolites and the intestinal barrier.
- Combining FMT with existing therapies like immunotherapy could offer new treatment avenues.

## Abstract

The clinical management of bladder cancer faces major challenges due to treatment resistance and recurrence, which require the development of new adjuvant strategies. The role of the gut microbiome in influencing bladder cancer progression and treatment response through the “gut-bladder axis” is gaining recognition. This understanding provides a theoretical rationale for exploring microbiota-targeting interventions, such as fecal microbiota transplantation (FMT). As a method capable of thoroughly reshaping the gut microbiota, FMT may have broad clinical potential. This review systematically explores the possible role of FMT in treating bladder cancer. It begins by summarizing the observational and causal evidence linking gut microbiota dysbiosis to bladder cancer, which forms the rationale for considering FMT as an intervention. Then, it discusses how FMT might improve therapeutic effectiveness, including regulation of microbial metabolites (such as short-chain fatty acids, tryptophan, and bile acids), repair of the intestinal barrier, induction of epigenetic reprogramming and modulation of the urinary microbiota. The review also considers potential scenarios for combining FMT with existing adjuvant therapies, including immunotherapy, chemotherapy, and radiotherapy. Finally, it objectively evaluates the key challenges in translating FMT into clinical practice, including effectiveness, safety, standardization, and regulatory or ethical issues, and outlines future directions. By synthesizing current evidence, this review highlights FMT as a potentially promising and innovative adjuvant strategy worthy of further investigation, which, if validated, could contribute to overcoming current therapeutic challenges in bladder cancer.