THE MICROBIAL LANDSCAPE OF ULCERATIVE COLITIS IN ENDOSCOPIC REMISSION. (22nd January 2022)

• Record Type: Journal Article
• Authors: Jangi, Sushrut; Robison, Glenn; Sebastiani, Paola; Crott, Jimmy; Weinstock, Joel; Singh, Siddharth; Michaud, Dominique
• Is Part Of: Inflammatory bowel diseases. Volume 28(2022)Supplement 1
• Page Start: S69
• Page End: S70
• Publication Date: 2022-01-22
• Subjects: Inflammatory bowel diseases -- Periodicals; Colitis, Ulcerative -- Periodicals; Crohn Disease -- Periodicals; Inflammatory Bowel Diseases -- Periodicals; 616.344
• DOI: 10.1093/ibd/izac015.113
• Languages: English
• ISSNs: 1078-0998

Abstract

Abstract: BACKGROUND: Achieving endoscopic remission (Mayo endoscopic score of 1 or 0) appears to be the optimal clinical target in ulcerative colitis, reducing risk of relapse, hospitalizations, complications, and need for surgery. While attaining complete endoscopic remission (MES 0) appears to reduce these risks further over mild endoscopic activity (MES 1), the etiologic factors for why MES 0 might be the superior target is poorly understood. Given the putative role of the gut microbiome in driving underlying endoscopic activity and subsequent relapse risk, we sought to define the microbial landscape of UC among patients who achieve either MES 0 vs MES 1 endoscopic remission, especially since the colonic microbial constituents of UC in remission remain uncharacterized. METHODS: We performed a retrospective cohort study, utilizing data from The Study of a Prospective Adult Research Cohort with IBD (SPARC IBD), part of the IBD Plexus network established by the Crohn's and Colitis Foundation. SPARC IBD is a national, multi-center, longitudinal cohort study enrolling eligible (>= 18 years) patients with IBD that includes demographic and disease specific clinical data, endoscopic scores, and stool metagenomics. To examine the microbiome, we evaluated beta-diversity (Bray-curtis dissimilarity), and phylum and genera-level differential taxal abundance, utilizing linear models (limma), between patients with UC in either MES 1 vs MES 0 endoscopic remission. Statistical analysis was performed using phyloseq and limma packages in R (ver 4.1). RESULTS: Within the SPARC cohort, we identified 77 patients in endoscopic remission (48 with MES 0, 29 with MES 1), of which 52% were female and 91% white, with median age of 48. Patients in MES 0 or MES 1 had no significant differences in exposure to anti-TNF therapy (50% vs 50%), vedolizumab (25% vs 19%) or mesalamine (69% vs 72%). Beta-diversity was similar between MES 0 and MES 1 remission [Figure 1]. Both MES 1 and MES 0 remission were dominated by Bacteroidetes and Firmicutes, and were specifically abundant for Bacteroides uniformis, unclassified Subdoligranulum, and Akkermansia mucuniphila . Compared to MES 1 remission, patients with MES 0 remission had increased abundance of Bacteroidetes, Firmicutes, and Actinobacteria, but reduced levels of Proteobacteria and Verrucomicrobia, although after adjusting for multiple comparisons, differential abundance at the phylum and taxa-level between both groups were comparable [Figure 2]. CONCLUSIONS: The microbial landscape of ulcerative colitis in MES 1 vs MES 0 endoscopic remission is comparable with respect to beta-diversity, phylum and genera-level differential taxal abundance. Further investigation will include comparison of UC in remission to healthy controls, and whether the presence of specific microbial groups in remission can predict subsequent relapse.