AB0492 INTESTINAL MICROBIOTA COMPOSITION OF PATIENT’S WITH BEHCET’S DISEASE: DIFFERENCES BETWEEN EYE, MUCOCUTANEOUS AND VASCULAR INVOLVEMENT (RHEUMA-BIOTA STUDY)
Authors: N. S. Yasar Bilge, V. Perez Brocal, T. Kaşifoğlu, U. Bilge, N. Kasifoglu, A. Moya, E. C. Dinleyici
Journal: Annals of the Rheumatic Diseases (2020)

Background: Recently, it has been shown that changes in microbiota composition play a role in the etiology and pathogenesis of chronic diseases. Changes in oral and intestinal microbiota diversity and composition are suggested in Behcet disease (BD), however there are no study available about the potential gut microbiota changes among different clinical forms of BD. Objectives: The aim of this study was to evaluate the intestinal microbiota composition of patient with BD and healthy controls, and also compare BD patients regarding to their eye, mucocutaneous and vascular involvement. Methods: In this prospective cohort study,27 patients diagnosed with BD and 10 aged and sex matched healthy controls were included. Patients with a body mass index&gt; 35, who have used antibiotics or probiotics in the last 4 weeks, patients with chronic gastrointestinal or other systemic diseases, and those with acute / severe gastrointestinal symptoms requiring medical treatment were excluded from the study. For the intestinal microbiota analysis, gene amplification, library formation, sequence analysis and bioinformatic evaluation of the results were performed with 16SrRNA next generation sequencing methods with Illumina MiSeq. Results: There was no difference between the BD group and the control group in terms of alpha (Chao-1 and Shannon) and beta (Bray-Curtis) microbiota diversity indices (p&gt; 0.05). Actinomyces, Libanicoccus, Collinsella, Eggerthella, Enetrohabdus, Catenibacterium and Enterobacter were significantly higher in BD group compared to the control group. In addition, Bacteriodes, Cricetibacter, Alistipes, Lachnospira, Dielma, Akkermansia, Sutterella, Anaerofilum, Ruminococcease-UCG007, Acetanaerobacterium; and Copropaacter were lower than the control group. There was no difference between the uveitis, mucocutaneous and vascular involvement groups in terms of alpha (Chao-1 and Shannon) and beta (Bray-Curtis) microbiota diversity and wealth indices (p&gt; 0.05) while we obtained a significant p value of the beta diversity between three groups in weighted UniFrac PCoA (p&lt;0.05). When we compared 3 three different system involvement (Eye, Mucocutaneous and Vascular), The LEfSe provides us with cladograms of six-level (from kingdom to genus). We found difference for the genera Lachnospiraceae NK4A136 in uveitis group, Dialister, İntestinomonas and Marvinbryantia in mucocutaneous group and Gemella in vascular involvement group. Conclusion: There was a significant difference in the composition of intestinal microbiota in Behçet’s disease compared to healthy adults. We found also found the different clinical forms of Behcet’s disease have some different gut microbiota composition. Especially in Behçet’s disease, it will be useful to evaluate Catenibacterium, Collinsella and Eggerthella increase, Bacteroides and Akkermansia decrease in larger series. In addition, due to the increase in the Eggerthella lenta strain observed both in the FMF and Behcet patient group, it is useful to make more detailed metagenomic analyzes regarding the role of this agent in the etiopathogenesis and course of rheumatic diseases. Disclosure of Interests: None declared