Dietary triacylglycerol digestion and absorption and bile acid status in neonatal piglets: a model for preterm human infants
Preterm infants and neonatal suckling piglets have a limited bile acid pool that may hinder absorption of dietary fatty acids, triacylglycerols (TAGs), and other lipid-soluble nutrients. Because dietary lipids are a valuable source of energy for growth, it is important for that TAGs be efficiently absorbed and utilized. The hypothesis of this study is that oral administration of 0.2 g/kg body weight daily of cholylsarcosine, an artificial bile acid, would decrease fecal excretion of dietary fatty acids and TAGs in suckling piglets. Twelve 7-d-old piglets were housed individually in metabolism cages and fed a commercial milk replacer with or without oral cholylsarcosine until 21 d of age. At 14 d of age, 13C hexadecanoic acid and tri-(D31 hexadecanoic acid) were administered orally to quantify absorption of dietary fatty acids and TAG. Cholylsarcosine treatment decreased fecal excretion of stearic acid (18:0) and palmitic acid (16:0) (P [less than or equal to] 0.02). Cholylsarcosine supplementation had no effect on absorption of unsaturated fatty acids of 16 or 18 carbons (P > 0.05). Oral supplementation with cholylsarcosine increased fecal excretion of deoxycholic acid (P = 0.03). Cholylsarcosine tended to stimulate greater incorporation of palmitic acid from dietary TAG into the free fatty acids in blood lipids (P = 0.135). Cholylsarcosine did not change incorporation of palmitic acid into plasma TAGs when fed as free palmitic acid or palmitic acid in TAG. Apparent absorption of dietary TAGs was increased from 77% in piglets not fed cholylsarcosine to 83% in the piglets that did receive oral cholylsarcosine. Together, these results support the hypothesis that cholylsarcosine increases absorption of dietary TAGs.