ABSTRACT
Short chain fatty acids(SCFA) are produced in the large bowel of humans by anaerobic bacterial fermentation.The main fermentative substrates are undigested dietary carbohydrates,including nonstarch polysaccharides and resistant starch(RS).SCFA are major organic acids in the lumen of the large intestine.They are preferred energy source for colonocytes.Their effects include enhancement of electrolyte uptake,stimulation of colon epithelial cell proliferation and mucosa growth,modulation of colonic immune function,nutritional support and protection of colon mucosa.Butyric acid can suppress colon neoplasm cell proliferation,induce its apoptosis and differentiation,affect proto-onc genes expression,which suggest that butyrate may be an important agent in cancer treatment.