DOP50 Impact of Inflammatory Bowel Disease associated dysbiosis on bacterial quorum sensing mediated by Acyl-homoserine Lactone in human gut microbiota

Abstract Background Intestinal dysbiosis is a key feature in the pathogenesis of inflammatory bowel diseases (IBD). Bacterial quorum sensing mediated by acyl-homoserine lactones (AHL) might play role dialogue between gut microbiota and host. The main objective our study was to investigate presence expression AHL synthase receptor genes human ecosystem during IBD. Methods To confirm gut, mass spectrometric detection performed on stool samples from IBD patients non-IBD subjects. Then, an silico approach, we exploited open access database: Inflammatory Bowel Disease Multi'omics Database, American cohort with bacterial metagenomes metatranscriptomes data characterise dysbiosis, most discriminating species were identified multivariate analysis allowed us define two groups (dysbiosis/non-dysbiosis). search for (luxI) (luxR) known homolog genes, using Basic Local Alignment Search Tool (BLAST) previously assembled gene files (presence/absence) as well raw sequencing (relative abundance expression). Results Mass spectrometry confirmed higher concentration molecules healthy subjects than relapsing Regarding analysis, 103 selected including 50 Crohn's disease (CD), 27 ulcerative colitis (UC), 26 No luxI-like retrieved BLAST searches. However, several homologs identified: sdiA Escherichia coli (7/103 patients) luxR-like Bacteroides fragilis dorei present all patients. According disease, only one under-expressed (p = 0.02) compared non-IBD, especially CD (Figure 1). In situation, luxR appeared be over-expressed 0.04) non-dysbiotic 2). Conclusion Through this computational AHL-synthesising bacteria have not been found. appears modulated IBD-associated dysbiosis. LuxR receptors, species, should investigated understand its impact 3). Targeting receptors represent new approach modulate