Delayed effects of early nutrition with cholesterol plus saturated or polyunsaturated fatty acids on intestinal morphology and transport function in the rat.

This study was undertaken to test the hypotheses that: (1) the fatty acid and/or cholesterol composition of a nutritionally adequate isocaloric semisynthetic diet given in early life has lasting consequences for intestinal nutrient uptake and morphology; and (2) early life feeding experiences with diets of varying fatty acid or cholesterol composition influence the ability of the intestine to adapt to an altered nutrient uptake in later life. Weanling female Sprague-Dawley rats were fed nutritionally adequate isocaloric semisynthetic diets enriched with beef tallow, beef tallow plus 1% cholesterol, fish oil or fish oil plus 1% cholesterol. Animals fed fish oil or fish oil plus cholesterol for 11 weeks had a lower food intake but greater weight gain than animals fed beef tallow or beef tallow plus cholesterol. The age of the animals influenced lipid and hexose uptake. The uptake of these nutrients could also be changed by the addition of cholesterol to the diet. This cholesterol-related effect depended on the type of fat in the diet (saturated vs. polyunsaturated). These changes in nutrient uptake were associated with but not necessarily explained by alterations in food intake, body weight gain, intestinal mucosal weight or surface area. Finally, these changes in nutrient uptake and morphology may or may not be reversible. We speculate that dietary lipids may affect the ability of the intestine to adapt to an altered nutrient intake in later life.