The Role of Gut Microbiome in Prostate Cancer: Current Evidence and Emerging Opportunities

Prostate cancer (PCa) is one of the most common malignancies in men, and growing evidence implicates the gut microbiome as a significant, modifiable contributor to disease evolution and management. Dysbiosis influences PCa biology through effects on inflammation, immune regulation, metabolism, and hormone signaling. Microbial imbalance can promote systemic inflammation and increase intestinal permeability, activating immune signaling pathways such as NF-κB–IL-6–STAT3. In parallel, microbiome-driven metabolic effects, including IGF-1 signaling and microbial androgen synthesis or recycling, may contribute to resistance to androgen deprivation therapy (ADT). Microbial metabolites, notably short-chain fatty acids (SCFAs) and trimethylamine N-oxide (TMAO), exert context-dependent effects on tumor growth, treatment resistance, and progression. Conversely, beneficial microbes have been associated with improved treatment sensitivity and immune regulation. Together, these insights support the gut microbiome as a potential biomarker and emerging therapeutic target in PCa. Modulation strategies, including diet, probiotics, antibiotics, and fecal microbiota transplantation (FMT), are being explored to improve treatment response and address resistance. As mechanistic evidence continues to grow, ongoing monitoring of the gut microbiome may help inform risk stratification and treatment optimization in prostate cancer.