Simulated In Vitro Infant Gastrointestinal Digestion of Infant Formulas Containing Different Fat Sources and Human Milk: Differences in Lipid Profiling and Free Fatty Acid Release

Simulated in vitro infant gastrointestinal digestion of human milk and four infant formulas containing different fat sources was analyzed and compared in this study. Although there are disadvantages brought about by its larger droplet size than infant formulas, human milk exhibited a higher lipolysis level due to the presence of MFGM interfacial layers. Higher hydrolysis efficiency of infant formulas (IFB, IFC, and IFM) was due to the presence of MFGM/phospholipid-enriched materials. Human milk released higher free fatty acid levels, especially long-chain fatty acid, and less undigested TAG molecules at the end of digestion than infant formulas. Human milk had a higher proportion of MAG and DAG linked to long-chain fatty acid. Furthermore, several lipids were identified as potential biomarkers that could be used to further analyze differences in the biological properties of human, bovine, and caprine milk. This comprehensive analysis might be fruitful to formulate an infant formula closest to human milk.