Trial Targeting Gut Bacterial Androgen Production to Reverse Therapeutic Resistance to Abiraterone in Patients With Metastatic Prostate Cancer

This trial is investigating whether targeting a specific type of gut bacteria that produce androgens (male hormones) can help reverse resistance to abiraterone — a hormone therapy commonly used for prostate cancer. Some prostate cancers stop responding to abiraterone because gut bacteria continue producing the hormones that fuel cancer growth; this study tests whether an antibiotic (metronidazole) can disrupt that process. **You may be eligible if...** - You are a male 18 years or older - You have been diagnosed with prostate cancer (adenocarcinoma) - Your PSA level is 2.0 ng/mL or higher - Your cancer has progressed while on abiraterone and prednisone for at least 12 weeks - You are on hormone-suppressing therapy (GnRH analogue) or have had surgical removal of the testes - Your life expectancy is at least 6 months - You are willing to collect urine and stool samples and abstain from alcohol during the study **You may NOT be eligible if...** - You have an active infection that makes steroid use dangerous - You require high doses of corticosteroids for another condition - You have significant liver disease Talk to your doctor to see if this trial is right for you.