Small intestinal mucosal transcriptomics in IBS

Irritable bowel syndrome (IBS) patients often experience meal associated symptoms. Our objective was to determine small intestinal mechanisms of lipid-induced symptoms and rectal hypersensitivity in IBS based on RNA-seq. Overall design: We recruited 26 IBS patients (12 IBS-C, 14 IBS-D) and 15 healthy volunteers (HV). In vivo permeability was assessed using saccharide excretion assay. Rectal sensitivity was assessed before and after a 1-hour small bowel lipid infusion (2 mL/min) and symptoms assessed throughout. Next, an extended upper endoscopy with probe-based confocal laser endomicroscopy (pCLE) was performed with changes assessed following application of intraluminal lipids. Mucosal biopsies from duodenum and jejunum were obtained for bulk RNA sequencing (RNA-seq). After library size selection of RNA-seq data, 11, 10, 12 Duodenum samples for HV, IBS-C and IBS-D were kept, and 12, 7, 8 Jejunum samples for HV, IBS-C and IBS-D were kept for further analysis.