Butyrate, Bacteroides thetaiotaomicron and Campylobacter jejuni modulate the expression of beta-defensins, Toll-like receptors and cytokines in Caco-2 cells

Abstract

Dietary fibre fermentation produces short-chain fatty acids, including butyrate (NaB). NaB increases histone tail acetylation within the chromatin of colonic cells, a process associated with increased gene expression. Campylobacter jejuni a prominent foodborne pathogen triggers inflammatory enteritis, whereas NaB and the commensal enteric bacterium Bacteroides thetaiotaomicron (B. theta) have documented anti-inflammatory properties. In this study I have developed a model system for studying the NaB-colonocyte-bacteria interaction and have used it to investigate responses to NaB, C. jejuni and B. theta using an in-house immunomodulatory gene array. NaB induced significant levels of transcription for nearly every immunomodulatory gene. Further, NaB and B. theta stimulate the expression of defensins and Toll-like receptors, while C. jejuni decreased both. This study provides mechanistic insights into the human colonocyte immune response and presents several gene targets as potential biomarkers for inflammatory expression responses in vivo.