Effect of fructooligosaccharide on nutritional parameters and mineral bioavailability in rats

The effect of fructooligosaccharide on protein digestibility and mineral absorption was studied in rats fed diets containing 5 g kg(-1) fructooligosaccharide, 5g kg(-1) cellulose/fructooligosaccharide (1: 1) or 5 g kg(-1) cellulose as a source of dietary fibre. Addition of cellulose/fructooligosaccharide or fructooligosaccharide to the diet did not significantly modify the daily food intake and food efficiency. However, the fructooligosaccharide-fed group showed a significant decrease in body weight gain compared with cellulose-fed groups. Faecal excretion was significantly lower when there was fructooligosaccharide intake, despite there being no significant differences in cellulose-fed groups. Intake of fructooligosaccharide produced an increase in caecal content and an enlargement of the caecal wall. This trophic effect could be attributed to short-chain fatty acids produced from the anaerobic fermentation of fructooligosaccharide by intestinal bacteria. Cellulose/fructooligosaccharide enhanced the apparent absorption and apparent retention of Ca, Mg, Zn and Fe. Fructooligosaccharide-fed rats experienced an increase in apparent absorption and apparent retention of Mg compared with cellulose-fed rats. Fructooligosaccharide intake at the lowest dose was enough to provide a desirable effect on mineral bioavailability in rats without any modification of nutritional parameters. (C) 2002 Society of Chemical Industry.