Preliminary results from a multicenter, randomized trial using fecal microbial transplantation to induce remission in patients with mild to moderate Crohn's disease.

Introduction: Fecal microbial transplantation (FMT) has shown promise at inducing remission in ulcerative colitis. This study is the first of its kind to evaluate the efficacy and safety of FMT at inducing remission in Crohn's disease (CD).

Methods: This double-blind, placebo-controlled trial was conducted in three Canadian academic centers; randomized patients with mild to moderate CD received FMT or placebo. The first treatment was administered by colonoscopy followed by weekly fecal capsules for 7 weeks. Primary endpoint was clinical and endoscopic remission at week 8. Secondary outcomes included clinical and endoscopic response, adverse events, and health-related quality of life using generic and disease-specific instruments.

Results: From July 2017 to June 2021, 21 and 13 patients were randomized to FMT and placebo groups, respectively. The trial terminated early due to futility. At week 8, 0% (0/15) of patients in the FMT group versus 8.3% (1/11) in the placebo group reached the primary endpoint of combined clinical and endoscopic remission as per protocol analysis. There were no differences between the groups in clinical or endoscopic responses. One participant in each group had worsening of CD. Although both groups experienced statistically significant improvements in health-related quality of life, only the FMT group had a significant decrease in activity impairment. Although there were no significant changes in microbial diversity or composition, participants who achieved clinical response became more similar to their donors in stool microbial composition.

Discussion: FMT was not effective at inducing clinical and endoscopic remission in CD using the FMT regimen in this study. Future studies may use other strategies to enhance treatment response, including longer intervention, antibiotic pretreatment, optimized donor-recipient pairing, and concomitant anti-inflammatory diet, biologic or small molecule therapies.