Dietary lipid droplet size and phospholipids modulate lipid digestion and absorption in early life nutrition, an in vitro study.

Lipid droplet structure differs in infant nutrition and may impact lipid digestion and absorption. Human milk (HM) contains large milk fat globule membrane (MFGM) coated lipid droplets, while standard infant formula (sIF) and sIF with added MFGM (sIFM) contains small protein coated droplets. Concept infant formula (cIF, Nuturis®) mimics HM's fat globule structure. Digestion of the infant formulae (IFs) and HM was simulated under infant conditions. Digests were sampled in time and free fatty acids (FFA) were analyzed to determine lipolysis rates. Lipid absorption was tested by digest incubation on Caco2/TC7 transwells for 6 h and 16 h. sIF and sIFM had higher lipolysis rates than cIF and HM. FFA release patterns differed between the IFs and HM. On Caco-2/TC7 cells, sIFM showed increased triglyceride secretion and larger intracellular lipid droplets compared to sIF. Altogether, the sIF and sIFM had higher lipolysis rates, while cIF was closer to breast milk in lipolysis and absorption rate.