Third generation sequencing analysis detects significant differences in duodenal microbiome composition between functional dyspepsia patients and control subjects

Functional dyspepsia (FD) is a multifactorial disorder as its development may be based on several different pathophysiological mechanisms. Interaction of gut microbiome with the host has been proposed as a potential mechanism involved in the disease's pathogenesis.BACKGROUNDFunctional dyspepsia (FD) is a multifactorial disorder as its development may be based on several different pathophysiological mechanisms. Interaction of gut microbiome with the host has been proposed as a potential mechanism involved in the disease's pathogenesis.We aimed to characterize microbiome profiling on duodenal luminal content (DLC) of FD patients and compare it to that of controls (CG) and patients with irritable bowel syndrome (IBS). Outpatients fulfilling Rome IV criteria for FD, IBS, and control group (CG) underwent upper gastrointestinal endoscopy and 2 cc of duodenal aspirate (3rd - 4th part) was aspirated in sterile traps. Duodenal microbiome was assessed after DNA extraction and 16S gene-based sequencing on Oxford Nanopore MinION followed by EPI2ME analysis (ONT/Metrich-ore Ltd). Bioanalysis of the microbiome (alpha-, beta-diversity, comparisons of relative abundances for all taxonomic ranks) was implemented in Python. Multiple group means comparisons were performed with one-way Analysis of Variance (ANOVA) and Kruskal-Wallis test with Tuckey's and Dunn's post hoc tests respectively, in case of significance (P-value