To determine the butyrate transport capacity in vitro and in tissue samples from healthy individuals and from patients with digestive disorders

Butyrate is a short chain fatty acid (SCFA) produced in the colon by microbial fermentation of otherwise indigestible carbohydrate fibres. Butyrate is the main energy source for colon cells, it can boost our immune system and affect intestinal functioning. Faecal butyrate concentrations are reported in the majority of clinical studies to date, however faecal concentrations of butyrate provide little information about the actual butyrate concentration in the colon and the flux (uptake) to the host. The uptake of butyrate is of particular importance given that many of butyrate’s effects are dependent on its intracellular concentration.The specific carrier-mediated transport systems (monocarboxylate transporter 1 (MCT1) and sodium-coupled monocarboxylate transporter 1 (SMCT1)), involved in the transport of butyrate from the colonic lumen into colonic epithelial cellshave been shown to be reduced in patients with inflammatory bowel disease (IBD).A reduction in butyrate uptake may have a profound effect on colon health since less butyrate would enter the cells.

In this project, gene expression levels of butyrate transporters and receptors will be analysed in fibroblasts, Caco-2 cells and colonic biopsies from healthy individuals, IBS patients and a subset of IBS patients classified as Post Infectious-IBS. The biopsies have already been collected and are available at the laboratory of the Gut Health research group. Furthermore, specific factors affecting the transportation of butyrate such as its ionic dependency (Na+, Cl-, H+) and effects of differences in pH in the transport properties of butyrate will be analysed in the in vitro models.