POS1353 COMPOSITION AND ASSOCIATIONS OF THE GUT MICROBIOTA IN BECHET’S DISEASE WITH PERIPHERAL LYMPHOCYTE SUBSETS AND CYTOKINES

Abstract

BackgroundBechet’s disease (BD) is a chronic multisystemic vasculitis with genetic and abnormal immune response. Growing evidences suggests gut microbiota compositional alteration may have an association with immune dysfunction in patients with BD.ObjectivesThis study aims to investigate the gut microbiota between BD and healthy controls (HCs) and analyse relevancy between bacterial and peripheral lymphocyte subsets and cytokines.MethodsFecal samples obtained from 22 BD patients and 22 normal-age and gender-matched HCs in this study. The gut microbiota were assessed with 16s rRNA sequencing and the flow cytometry was used to dectect peripheral lymphocyte subsets. C-reaction protein (CRP), Erythrocyte sedimentation rate (ESR), complement C3 and C4 were also assigned for disease activity measure. The edgeR package was used for differential abundance analysis. Difference of alpha diversity indices, bacterial abundances, and the F/B ratio were carried out using the Wilcoxon rank-sum test (R v.4.0.1). The differential abundance of flora and CRP, ESR, C3 and C4 between BD patients and HCs was assessed by pearson’s correlation analysis.ResultsAs for alpha diversity, the Shannon (p < 0.05) and Simpsonance analysis. Difference of alpha diversity indices, bacterial abundances, and the F/B ratio were carried out using the Wilcoxon rank-sum test (R v.4.0.1). The differential abundamicrobial community structures between BD and HCs (R = 0.053, p = 0.051; Figure 1B). The gut microbiota compositions of BD differed form those of HCs (Figure 1C). Four species of flora distinctly difference were found in BD (p < 0.05; Figure 1D). There was significant positive correlations between Tregs and Verrucomicrobiota (p < 0.05), and Proteobacteria (p < 0.05), Th1 and Proteobacteria (p < 0.05), ESR and Verrucomicrobiota (p < 0.01), but negatives correlation between TNF-α and Desulfobactbiota (p < 0.05; Figure 1E).ConclusionPattients with CTD had disbiosis of gut microbiota charaterized by impared diversity and abnomal composition, which was closely correlated with peripheral lymphocyte subsets and disease activity measures.References[1]Margaret Alexander, Qi Yan Ang, Renuka R Nayak, et al. Human gut bacterial metabolism drives Th17 activation and colitis. Cell Host Microbe. 2022 Jan 12;30(1):17-30.e9. doi: 10.1016/j.chom.2021.11.001. Epub 2021 Nov 24.[2]Yi-Wen Tsai, Jia-Ling Dong, Yun-Jie Jian, et al. Gut Microbiota-Modulated Metabolomic Profiling Shapes the Etiology and Pathogenesis of Autoimmune Diseases. Microorganisms. 2021 Sep 10;9(9):1930. doi: 10.3390/microorganisms9091930.AcknowledgementsThis work was supported by the National Natural Science Foundation of China (No. 82001740).Disclosure of InterestsNone declared