Preterm Pigs Fed Donor Human Milk Have Greater Liver β-Carotene Concentrations than Pigs Fed Infant Formula

Milk carotenoids may support preterm infant health and neurodevelopment. Infants fed human milk often have higher blood and tissue carotenoid concentrations than infants fed carotenoid-containing infant formula (IF). Donor human milk (DHM) is a supplement to mother’s own milk, used to support preterm infant nutrition. We tested whether tissue and plasma β-carotene concentrations would be higher in preterm pigs fed pasteurized DHM versus premature IF. This is a secondary analysis of samples collected from a study of the effects of enteral diet composition on necrotizing enterocolitis incidence. Preterm pigs received partial enteral feeding of either DHM (n = 7) or premature IF (n = 7) from 2 to 7 d of age. The diets provided similar β-carotene (32 nM), but DHM had higher lutein, zeaxanthin, and lycopene, whereas IF had higher total vitamin A. Plasma, liver, and jejunum carotenoid and vitamin A concentrations were measured by HPLC-PDA. Jejunal expression of 12 genes associated with carotenoid and lipid metabolism were measured. Liver β-carotene concentrations were higher in DHM- than IF-fed piglets (23 ± 4 compared with 16 ± 2 μg/g, respectively, P = 0.0024), whereas plasma and jejunal β-carotene concentrations were similar between diets. Liver vitamin A stores were higher in piglets fed IF than DHM (50.6 ± 10.1 compared with 30.9 ± 7.2 μg/g, respectively, P=0.0013); however, plasma vitamin A was similar between groups. Plasma, liver, and jejunum concentrations of lutein, zeaxanthin, and lycopene were higher with DHM than IF feeding. Relative to piglets fed DHM, jejunal low density lipoprotein receptor (Ldlr) expression was higher (61%, P = 0.018) and cluster determinant 36 (Cd36) expression (−27%, P = 0.034) was lower in IF-fed piglets. Preterm pigs fed DHM accumulate more liver β-carotene than IF-fed pigs. Future studies should further investigate infant carotenoid bioactivity and bioavailability.