Caecal parameters of rats fed diets supplemented with inulin in exchange for sucrose.

The effects of different modes of inulin supplementation on caecal fermentation were evaluated in rats. Groups S and IN were fed diets containing 5% of sucrose or inulin, respectively, for the whole experimental period of 40 days. Group IN/S was fed IN and S diets, whereas group S/IN was fed S and IN diets, in the first and the second 20-day period, respectively. Groups IN(up) and IN(down) were fed diets in which the content of inulin increased from 1-5% and decreased from 5-1%, every 8 days, respectively. The common effects of inulin on caecal fermentation, i.e. enlargement of tissue, acidification of digesta, a decrease in activities of potentially harmful bacterial enzymes (beta-glucuronidase and beta-glucosidase), and an increase in the total volatile fatty acids concentration and pool, were especially observed in the IN, S/IN and IN(up) groups. The results suggested that the intensity of caecal fermentation is increased when inulin is present at a relatively high dietary level and that these changes are easily reversible after inulin withdrawal from feed.