Effects of pectin and cellulose on fat absorption after massive small-bowel resection in weanling rats

The effects of pectin and cellulose on fat absorption after massive small-bowel resection were studied in rats. Weanling Wistar rats underwent 80% resection of the small intestine with gastrostomy, and fat emulsion labeled with 14C-linoleate was given via a gastrostomy tube for the fat absorption test on the 10th postoperative day. They were classified into three groups by diet as follows: E group, a fiber-free, chemically defined diet (CDD); EP group, CDD with 2% pectin; and EC group, CDD with 2% cellulose. The cumulative and hourly output of 14C in the expired air, the absorption rate of 14C in the intestine, and the metabolic utilization rate of 14C were calculated. The cumulative 14CO2 output was significantly lower in the EC group than in the E and EP groups. However, there was no significant difference in the 14CO2 output between the E and EP groups. The highest hourly 14CO2 output in the E and EP groups was observed during the first 2 hours. However, in the EC group, this fluctuated at low levels. No significant difference in the 1-14C-linoleate absorption rate was observed between the E and EP groups, whereas it was significantly lower in the EC group than in the E and EP groups. The metabolic utilization rate of 1-14C-linoleate showed no significant difference among the three groups. These data suggest that an addition of pectin to CDD does not impair small intestinal absorption of 1-14C-linoleate after massive small-bowel resection, and an addition of cellulose decreases absorption of 1-14C-linoleate.