fructooligosaccharide and Colonic-Neoplasms

Fructooligosaccharides (FOS) are oligosaccharides that occur naturally in plants such as onion, chicory, garlic, asparagus, banana, artichoke, among many others. They are composed of linear chains of fructose units, linked by beta (2-1) bonds. The number of fructose units ranges from 2 to 60 and often terminate in a glucose unit. Dietary FOS are not hydrolyzed by small intestinal glycosidases and reach the cecum structurally unchanged. There, they are metabolized by the intestinal microflora to form short-chain carboxylic acids, L -lactate, CO(2), hydrogen and other metabolites. FOS have a number of interesting properties, including a low sweetness intensity; they are also calorie free, non-cariogenic and are considered as soluble dietary fibre. Furthermore, FOS have important beneficial physiological effects such as low carcinogenicity, a prebiotic effect, improved mineral absorption and decreased levels of serum cholesterol, triacylglycerols and phospholipids. Currently FOS are increasingly included in food products and infant formulas due to their prebiotic effect stimulate the growth of nonpathogenic intestinal microflora. Their consumption increases fecal bolus and the frequency of depositions, while a dose of 4-15 g/day given to healthy subjects will reduce constipation, considered one of the growing problems of modern society, and newborns during the first months of life.

Topics: Blood Glucose; Carbohydrate Sequence; Colonic Neoplasms; Constipation; Dietary Carbohydrates; Fatty Acids, Volatile; Humans; Immune System; Infant; Infant Formula; Infant, Newborn; Insulin; Intestinal Absorption; Lipid Metabolism; Milk, Human; Minerals; Oligosaccharides; Prebiotics

This study investigated the inhibitory effects of soy isoflavones and fructooligosaccharide (FOS) on colon carcinogenesis. Sprague-Dawley male rats were injected with 1,2-dimethylhydrazine (DMH) and given experimental diets that contained 0%, 3%, 6%, or 9% FOS with or without soy isoflavones (1,000 mg/kg of diet). After 12 weeks, colonic aberrant crypt foci (ACF) formation, cyclooxygenase-2 (COX-2) expression, and fecal bile acid profiles were determined. The numbers of ACF, the numbers of ACF containing four or more crypts per focus of colonic mucosa, and the levels of COX-2 protein in the colonic epithelial tissues were significantly decreased in a dose-dependent manner in the FOS-fed, DMH-treated rats (P < .001), as compared to the DMH-treated control rats. Soy isoflavones significantly decreased the number of ACF with four or more aberrant crypts per focus (P < .001) and the amount of COX-2 protein (P < .01), independently of the effect of the oligosaccharide. The highest suppression of ACF formation was obtained with soy isoflavones combined with >or=6% FOS. No significant relationship was found between the dosage of FOS or soy isoflavones and the concentration of fecal secondary bile acid. We conclude that the combination of FOS and soy isoflavones inhibits colonic ACF formation and reduces COX-2 expression in DMH-treated rats.

Topics: Animals; Anticarcinogenic Agents; Bile Acids and Salts; Colon; Colonic Neoplasms; Cyclooxygenase 2; Dimethylhydrazines; Feces; Glycine max; Intestinal Mucosa; Isoflavones; Oligosaccharides; Rats; Rats, Sprague-Dawley