OLESTRA, A NONDIGESTIBLE, NONABSORBABLE FAT - EFFECTS ON GASTROINTESTINAL AND COLONIC TRANSIT

Olestra, the name proposed for the mixture of hexa-, hepta- and octaesters of sucrose and long-chain fatty acids, is a nondigestible, nonabsorbable lipid with physical properties and taste that are similar to those of natural triglycerides. Our aim was to determine whether substitution with up to 30 g of olestra in a 45-g fat meal would alter gastric, small bowel, and colonic transit. Five groups, each of six healthy volunteers, ingested 800-kcal, 22-g protein meals containing a total of 45 g of lipid (N = 24) or 15 g of lipid (N = 6). Among those receiving the 45-g fat meal, 0, 7.5, 15 and 30 g of lipid were substituted with olestra (N = 6 per group). The 15-g fat meal consisted entirely of natural triglyceride. A dual gamma camera scintigraphic method was used to estimate gastric and small bowel transit (Tc-99m pellets in the meal) and colonic transit (In-111 pellets). The latter was achieved by the delayed release of In-111 pellets from a capsule coated with a pH-sensitive polymer, methacrylate, that disintegrated in the terminal ileum. There were no differences in the gastric, small bowel, or colonic transits of any of the five equicaloric meals. Some individuals had a significantly greater 48-hr stool weight after ingesting 15 g of olestra, but stool weights of subjects consuming 7.5 g or 30 g of olestra did not differ from controls. We conclude that substitution with olestra of up to 30 g in a 45-g fat meal does not significantly alter gastrointestinal transit in healthy subjects.