Molecular structure and fatty acyl chain length-driven differences in digestive fate and intestinal cellular uptake: A comparative study of natural and structured triacylglycerols

This study utilized a simulated in vitro dynamic digestion model for infants, combined with lipidomics technology and a Caco-2 cell model, to systematically investigate the effects of triacylglycerol molecular structure and fatty acyl chain length in lipids on lipolysis and cellular uptake. The results indicated that medium- and long-chain triacylglycerols (MLCT) exhibited higher lipolysis efficiency during gastrointestinal digestion, with a greater final lipolysis degree and higher free fatty acid release compared to the physical mixture of MCT/LCT. Moreover, MLCT significantly promoted the expression of genes related to lipid uptake and transport ( CD36 , FABP4 , and SLC27A4 ) in intestinal cells. The composition of the digestion products of MLCT was highly correlated with its initial triacylglycerol structure. While providing medium-chain fatty acids, it can effectively release long-chain fatty acids, which better meets the physiological needs of lipid digestion and absorption in infants. This study provides a scientific basis for the precise application of MLCT as a functional lipid in infant formula.