STOP-CDI: Efficacy of Fecal Microbiota Transplantation vs Fidaxomicin vs Vancomycin in Treating and Preventing Relapse of Clostridioides Difficile Infection

This intervention consists of a two-phase treatment for Clostridioides difficile infection in high-risk adults. First, participants receive a short-course (5 days) of oral vancomycin to reduce C. difficile bacterial load. Following antibiotic pretreatment, fecal microbiota transplantation (FMT) is administered to restore healthy gut microbiota. FMT is delivered primarily via encapsulated microbiota capsules, with alternative routes including colonoscopy, gastroscopy, nasojejunal tube, or rectal enema if capsules are contraindicated. A second FMT dose is given 7 days after the first, either as daily capsules over six days or as a single endoscopic administration. This approach aims to reduce CDI recurrence by combining targeted antibiotic reduction of pathogens with microbiome restoration.

Participants receive a 10-day course of fidaxomicin administered orally at a dose of 200 mg twice daily. Fidaxomicin is a narrow-spectrum macrocyclic antibiotic specifically targeting Clostridioides difficile with minimal impact on the normal gut microbiota. This monotherapy aims to eradicate C. difficile infection while preserving the intestinal microbiome, thereby reducing the risk of recurrence. No additional interventions are provided during the treatment period. Biological samples are collected before and after treatment to evaluate clinical response, safety, and microbiome changes.

Participants receive a 10-day course of oral vancomycin at a dose of 125 mg four times daily. Vancomycin is a broad-spectrum glycopeptide antibiotic commonly used as standard-of-care therapy for Clostridioides difficile infection. This monotherapy aims to eradicate C. difficile by reducing bacterial load in the colon. No additional interventions are applied during the treatment period. Biological samples are collected before and after treatment to monitor clinical outcomes, safety, and changes in the gut microbiome.