4th Annual BMRP Investigator Meeting - Abstract

Novel Strategies for the Colonic Provision of Butyric Acid

Douglas Morrison^1,a, Christine Edwards², Tom Preston¹, Brian Dodson³ and Lawrence Weaver<sup>2

1</sup>SUERC and ²Division of Developmental Medicine, University of Glasgow (Glasgow, Scotland, United Kingdom); ³School of Science and Technology, Bell College of Technology (Glasgow, Scotland, United Kingdom)

Butyric acid is a natural product of the bacterial fermentation of non-digestible carbohydrates in the large intestine.  It has been shown to have potent anti-inflammatory properties both in vitro and in vivo.  We have investigated the routes of butyric acid production using isotope tracer techniques.  Some carbohydrates increase butyric acid production by selectively promoting bacterial conversion of acetate and lactate to butyric acid.  During oligofructose fermentation, these pathways dominate and account for ~80 % of newly synthesized butyrate.  We also examined the effect of terminal electron acceptors on butyrate production.  We observed an obliteration of butyrate production in the presence of nitrite, whilst other metabolites were only moderately affected.  Nitrate, sulfate and sulfite had no discernable effect on butyrate production.  To circumvent the difficulties associated with increasing colonic butyric acid production through diet and/or enema, we have developed a direct delivery system that can be consumed orally.  Oligofructose was chemically modified to effect direct delivery of butyric acid to the colon.  We have shown in human volunteers, using isotope labeling methods, that modified oligofructose delivers >90% of its butyric acid to the colon.  These delivery vehicles represent a new approach to selectively modulating colonic butyric acid production and will permit clinical studies to test the efficacy of butyric acid in IBD.

^aPrincipal Investigator