PD1 Inhibitors Combined With Clostridium Butyricum for Urothelial Carcinoma

This study is testing whether combining an immunotherapy drug (a PD-1 inhibitor) with a probiotic supplement (Clostridium butyricum) before or after bladder cancer surgery can improve outcomes for people with urothelial (bladder) carcinoma. **You may be eligible if...** - You have muscle-invasive bladder cancer (stage T2-T4a) with no lymph node or distant spread, and are being considered for pre-surgery treatment, OR - Your post-surgery pathology showed advanced stage (T3-T4) or positive lymph nodes **You may NOT be eligible if...** - Your surgeon determines you cannot safely undergo radical surgery - You have previously received chemotherapy or immunotherapy for this cancer - You have an active autoimmune disease requiring systemic treatment - You require long-term high-dose steroids or other immunosuppressive drugs Talk to your doctor to see if this trial is right for you.