Colonoscopic Diagnostic Features of Stool and Mucosa of Inflamed versus Healed Ulcerative Colitis After Repeated Fecal Microbiota Transplantation

Abstract

Introduction: Following the first ulcerative colitis (UC) patient treated successfully using Fecal Microbiota Transplantation (FMT) in our Clinic in 1988 to later reporting 6 patients in 2003, we observed colonic appearances during repeated FMT treatment. An unusual phenomenon was noticed endoscopically of the stool changing from messy attachment to mucosa to spherical pellets unattached as the colitis rapidly healed. With the recent increase of repeated FMT as an UC treatment, and after we reported this noticeable colonic appearance1, we have now collected data retrospectively during FMT-evoked healing. A comparison of these with inflammatory markers gives credence to our view that the spherical stool appearance indicates healing UC. Methods: A retrospective analysis was completed on a total of 10 patients undergoing repeated FMT treatment with photographs taken pre- & post- during unprepared colonoscopy. These were correlated with CRP and histological inflammation levels. Paired t-tests were used to assess change in biomarkers. Significance was set at p < 0.05. Results: In all 10 patients, initial observations of ongoing inflammation were seen during bowel ‘prep' colonoscopy. Post-FMT colonoscopic appearances showed stool ‘smeared' over inflamed mucosa requiring cleaning with a jet of water to see the state of the mucosa. A later unprepared colonoscopy revealed spherical pellets of stool we believed to be a sign of mucosal healing (Figure 1). All 10 patients with normal-looking mucosa after treatment showed visible fine blood vessels and no granularity. Histological inflammatory change was confirmed in 5 patients via biopsy results, with the remaining 5 not having either pre- or post-treatment biopsy data. The biomarker change observed in CRP tended to be reduced post-treatment (p=0.086).Figure: Left: Transverse colon pre-treatment with smeared stool in inflamed mucosa. Right: Transverse colon post-treatment with spherical pellets of stool showing normalizing mucosa.Conclusion: The colonoscopic appearance change in UC treatment with repeated FMT appears to be a useful clinical indicator of resolving colitis, and it correlates with the small improvement in CRP and histology. It is likely that other therapies achieving deep mucosal healing may also exhibit such an appearance. However, given the use of FMT and not disturbing the gut microbiome with a bowel ‘prep', we have inadvertently observed this phenomenon which otherwise might have been missed in purged colonoscopies. Further future correlation with calprotectin levels may lead to identifying endpoint indicators for repeated FMT.