The influence of the position of palmitate in infant formula triacylglycerols on health outcomes

The purpose of this review is to discuss recent studies reporting on the influence of the position of palmitic acid in triacylglycerols in infant formula and relevant animal studies. Earlier experiments in rodents show that a diet with a higher proportion of palmitate at the sn-2 position of triacylglycerols improves dietary fat and calcium absorption compared with a diet with a lower sn-2 palmitate content. A high-sn-2 palmitate diet increased fecal short-chain fatty acids, reduced gut inflammation in a colitis model, and altered tissue endocannabinoid concentrations in laboratory rodents. Recent studies in infants confirm that formula with a high sn-2 palmitate content reduces stool fat, palmitic acid, fat soaps, palmitate soaps, and calcium compared with formula with a low sn-2 palmitate content. These effects have been associated with improved bone strength, increased fecal bifidobacteria, and reduced crying in infants. In some studies, findings with formula high in sn-2 palmitate match those seen in breast-fed infants. However, in many studies, high sn-2 palmitate formula remains inferior to breast-feeding. It is concluded that infant formula high in sn-2 palmitate is superior to formula with low sn-2 palmitate but does not fully match human breast milk. Recent studies showing altered gut microbiota (human infants) and tissue endocannabinoids (rodent model) suggest the potential for marked physiological impact of high sn-2 palmitate that needs to be explored further in human trials.