Uptake of lipids into rabbit jejunum and colon following ileal resection. Effect of variations in dietary content of carbohydrate.

This study was undertaken to determine the effect of variations in the dietary content of carbohydrate (sucrose) and intestinal resection on the passive jejunal and colonic uptake of short-, medium-, and long-chain length fatty acids, cholesterol, and decanol. A previously validated in vitro technique was used, and studies were performed in sham-operated control animals and in rabbits submitted to the surgical removal of the distal half of the small intestine. After six weeks feeding of a high- or low-carbohydrate diet, the uptake of lipids was altered, but the direction and extent of changes was different among jejunum, ileum, and colon in control animals, and between the jejunum or colon of control vs resected animals. The intestinal membrane is likely heterogeneous with respect to passive permeability pathways since dietary manipulation of sucrose had a different effect on the uptake of each lipid probe. The finding of lower jejunal and colonic cholesterol uptake in animals fed a high- as compared with a low-carbohydrate diet reflects the importance of dietary effects on intestinal permeation. Studies must now be performed to establish the mechanisms responsible for these diet-related changes in intestinal permeability.