Protective pathways against colitis mediated by appendicitis and appendectomy

Summary Appendicitis followed by appendectomy (AA) at a young age protects against inflammatory bowel disease (IBD). Using a novel murine appendicitis model, we showed that AA protected against subsequent experimental colitis. To delineate genes/pathways involved in this protection, AA was performed and samples harvested from the most distal colon. RNA was extracted from four individual colonic samples per group (AA group and double‐laparotomy control group) and each sample microarray analysed followed by gene‐set enrichment analysis (GSEA). The gene‐expression study was validated by quantitative reverse transcription–polymerase chain reaction (RT–PCR) of 14 selected genes across the immunological spectrum. Distal colonic expression of 266 gene‐sets was up‐regulated significantly in AA group samples (false discovery rates