Long-term Efficacy and Safety of Fecal Microbiota Transplantation in Patients With Ulcerative Colitis

The pathogenesis of inflammatory bowel disease (IBD) is thought to result from a complex interplay of genetic predisposition, environmental factors such as diet and gut microbiota, and immunological mechanisms. Among these, increasing attention has been given to the role of the gut microbiota, which resides on the intestinal mucosal surface and plays a key role in regulating host immune responses. Emerging evidence suggests that alterations in gut microbiota, as well as viruses that influence microbial composition, are closely associated with IBD.

In 2013, a landmark study published in the New England Journal of Medicine demonstrated that fecal microbiota transplantation (FMT)-a procedure in which processed stool from a healthy donor is delivered into a patient's colon via colonoscopy-significantly reduced the recurrence of antibiotic-associated Clostridioides difficile infection. Since then, FMT has been actively studied, particularly for its therapeutic potential in ulcerative colitis, a subtype of IBD.

Randomized controlled trials have investigated various methods of FMT delivery in ulcerative colitis, including colonoscopy, sigmoidoscopy, and oral capsules. No significant differences in efficacy have been reported between endoscopic and oral routes. In a domestic study on multidrug-resistant organisms, oral capsules showed promising outcomes in restoring microbial balance when compared with endoscopy and nasogastric tube administration.

While FMT delivery methods in Western countries are evolving from inpatient colonoscopic administration to outpatient enema or capsule-based regimens, South Korea currently lacks clinical research infrastructure for FMT beyond case reports. Although a few cases of FMT in IBD patients have been documented, no center has conducted formal clinical trials.

Therefore, this study aims to evaluate the clinical efficacy and underlying mechanisms of FMT in Korean patients with IBD, especially those with ulcerative colitis. Through this investigation, we seek to clarify the long-term therapeutic potential and safety of fecal microbiota transplantation in this population.

• Co-secondary outcome [Time frame: The disease status will be evaluated at week 12 as the final assessment. Long-term efficacy and safety will also be analyzed at week 48(e.g., History of hospitalization, mortality, occurrence of malignant tumors, and adverse events[Safety]).]
• Co-secondary outcome [Time frame: The disease status will be evaluated at week 12 as the final assessment. Long-term efficacy and safety will also be analyzed at week 48(e.g., History of hospitalization, mortality, occurrence of malignant tumors, and adverse events[Safety]).]
• Co-secondary outcome [Time frame: The disease status will be evaluated at week 12 as the final assessment. Long-term efficacy and safety will also be analyzed at week 48(e.g., History of hospitalization, mortality, occurrence of malignant tumors, and adverse events[Safety]).]
• Co-secondary outcome [Time frame: The disease status will be evaluated at week 12 as the final assessment. Long-term efficacy and safety will also be analyzed at week 48(e.g., History of hospitalization, mortality, occurrence of malignant tumors, and adverse events[Safety]).]
• Co-secondary outcome [Time frame: The disease status will be evaluated at week 12 as the final assessment. Long-term efficacy and safety will also be analyzed at week 48(e.g., History of hospitalization, mortality, occurrence of malignant tumors, and adverse events[Safety]).]
• Co-secondary outcome [Time frame: The disease status will be evaluated at week 12 as the final assessment. Long-term efficacy and safety will also be analyzed at week 48(e.g., History of hospitalization, mortality, occurrence of malignant tumors, and adverse events[Safety]).]
• Co-secondary outcome [Time frame: The disease status will be evaluated at week 12 as the final assessment. Long-term efficacy and safety will also be analyzed at week 48(e.g., History of hospitalization, mortality, occurrence of malignant tumors, and adverse events[Safety]).]
• Co-secondary outcome [Time frame: The disease status will be evaluated at week 12 as the final assessment. Long-term efficacy and safety will also be analyzed at week 48(e.g., History of hospitalization, mortality, occurrence of malignant tumors, and adverse events[Safety]).]
• Co-secondary outcome [Time frame: The disease status will be evaluated at week 12 as the final assessment. Long-term efficacy and safety will also be analyzed at week 48(e.g., History of hospitalization, mortality, occurrence of malignant tumors, and adverse events[Safety]).]
• Co-secondary outcome [Time frame: The disease status will be evaluated at week 12 as the final assessment. Long-term efficacy and safety will also be analyzed at week 48(e.g., History of hospitalization, mortality, occurrence of malignant tumors, and adverse events[Safety]).]