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

This study aims to perform fecal microbiota transplantation (FMT) and analyze its effects in selected patients aged between 10 and 80 years who have been diagnosed with ulcerative colitis and have been receiving treatment for more than three months at Seoul National University Hospital, Seoul National University Boramae Medical Center, and Seoul National University Bundang Hospital. Through this analysis, the study seeks to identify the long-term efficacy of FMT as a treatment for ulcerative colitis, evaluate the safety of the procedure, and establish a foundation for personalized FMT based on gut microbiota analysis.

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.