BUTYRIC-ACID FROM THE DIET - ACTIONS AT THE LEVEL OF GENE-EXPRESSION

A number of components present in the diet, although nutritionally non essential, have been discovered to have beneficial effects toward both general health and disease prevention/protection. One such nutrient, butyric acid, can be derived in large quantities from bacterial fement ation of dietary fiber in the bowel and is also a component of bovine milk. In gut fermentation, the production of butyric acid defines its delivery point; thus, the synthesis and site of action of butyric acid are in close proximity and have frustrated the investigation of its a ctivities in vivo. Recent research has, however, revealed a number of activities of butyric acid toward isolated cells. In particular, its a bility to modify nuclear architecture and induce death by apoptosis in colon cancer cells is arousing great interest. Butyric acid changes t he structure of chromatin through its effects on posttranslational mod ifications, key modifications being acetylation and phosphorylation of the nuclear histones. Butyric acid can also modify the differentiatio n state of cells, and in the case of cancerous colonic cells overcomes their resistance to normal programmed death. Thus, the activities of this fermentation product of dietary fiber may contribute substantiall y to the decreased incidence of bowel cancer that has been associated with fiber intake.