Abstracts of the 13 th Congress of ECCO – European Crohn’s and Colitis Organisation S555 Conclusions: Sb shows an anti-infammatory effect on experimen- tal colitis and has a protective effect of intestinal mucosal mechani- cal barrier, which is as effective as mesalazine. Combined Sb with mesalazine does not show a better effect. Dysbacteriosis exist in DSS induced colitis, which are expressed in decreased Firmicutes and increased Proteobacteria. Sb can upregulate the abundance of fam- ily S24-7 specifcally, which may be a mechanism of its functioning. References 1. Guslandi M, Mezzi G, Sorghi M, et al. Saccharomyces boular- dii in maintenance treatment of Crohn's disease. Dig Dis Sci. 2000;45:1462–4. 2. Bourreille A, Cadiot G, Le Dreau G, et al. Saccharomyces bou- lardii does not prevent relapse of Crohn's disease. Clin Gastroen- terol Hepatol. 2013 ;11:982–7. P866 Faecal microbiota in newly diagnosed Crohn’s disease and its relation to treatment escalation S. Vatn 1 *, M.C. Karlsson 2 , A. Carstens 3,4 , T.E. Detlie 1,5 , P. Ricanek 1 , D. Bergemalm 3 , C.M. Lindquist 3 , J. Jahnsen 1,5 , J. Halfvarson 3 , C. Casèn 2 , M.H. Vatn 5 , IBD-character consortium 1 Akershus University Hospital, Akershus, Norway, 2 Genetic Analysis, 0510 Oslo, Norway, 3 Orebro University, Department of Gastroenterology, Faculty of Medicine and Healthy, Orebro, Sweden, 4 Ersta Hospital, Stockholm, Sweden, 5 University of Oslo, 0316 Oslo, Norway Background: Crohn’s disease (CD) is a chronic infammatory disease which can affect any part of the gastrointestinal tract. The treat- ment aims at inducing and maintaining remission based on clinical symptoms, endoscopic appearance and biochemical markers. Some patients have a mild disease course whilst other develop a refrac- tory disease or complicated disease behaviour, due to a stricturing/ penetrating phenotype , leading to treatment escalation. Tools for predicting the disease course are limited. Identifcation of microbiota signatures, might be a tool for identifcation of patient with a poor prognosis and need of treatment escalation. Methods: Fecal samples were obtained at diagnosis from 33 newly diagnosed CD patients in the IBD- character cohort. Fecal micro- biota composition was assessed using the GA-map™ Dysbiosis Test [Casén et al., 2015]. Disease course and treatment were followed up to 5 years after inclusion. The cohort was divided in two groups, one with a milder course and another with more severe disease progres- sion demanding treatment escalation, defned by introduction of bio- logic treatment and/or surgery after initial treatment. Comparisons between the groups were made using the Wilcoxon test. Results: Among 33 CD patients, 28 (85%) were classifed as dysbi- otic (11 mild and 17 severe). A total of 12 (36%) patients required treatment escalation. At the time of diagnosis, the dysbiosis index, did not discriminate between patients who did or did not require treatment escalation. Akkermansia muciniphila was found to be reduced in CD patients who required treatment escalation compared with those who did not (p = 0.04), while a component of unclassifed Clostridiales was found to be signifcantly increased in CD patients who required treatment escalation (p = 0.03). Conclusions: CD patients with an aggressive disease course exhibited a decreased abundance of Akkermansia muciniphila and an increased abundance of Clostridiales already at diagnosis. Our results might point to the relevance of these taxa for the discovery of predictive biomarkers that can be used to support tailored treatment in CD. P867 The role of gut microbiota in the formation of steroid resistance and dependence in patients with ulcerative colitis and Crohn’s disease N. Danilova 1 , S. Abdulkhakov 1,2 , T. Grigoryeva 2 *, M. Markelova 2 , S. Malanin 2 , A. Tyakht 3,4 , A. Pavlenko 4 , A. Odintsova 5 , R. Abdulkhakov 1 Downloaded from https://academic.oup.com/ecco-jcc/article-abstract/12/supplement_1/S555/4808490 by guest on 26 June 2020