Characterization and chronological changes of preterm human milk gangliosides.

Objective: Gangliosides are present in high concentrations in the nervous tissue, and some are observed in small amounts in many extraneural tissues and body fluids. Human milk may play important roles in energy supplementation, prophylaxis of infection, and brain development. For preterm infants, human milk gangliosides are also very important substances during the early lactation stage. However, there are no data on human milk gangliosides from mothers at preterm delivery. We investigated the characterization of gangliosides and chronologic changes in human preterm milk earlier than 30 wk of gestation from 1 to 60 d after birth.

Methods: Forty-one samples were analyzed by high-performance thin-layer chromatography and a microtechnique using 1 mL of milk from each lactation and compared with 61 full-term human milk samples.

Results: Total lipid-bound sialic acid of human milk gangliosides after preterm delivery showed a peak concentration at 2 to 3 d postpartum and then remained at a high concentration until approximately 10 d. GD3 was the major ganglioside in the colostrum until approximately 7 to 10 d postpartum. GM3 was scarcely detected until 7 d postpartum and then increased gradually. There was no difference in the GD3 concentration per 1 mL of human milk between preterm and full-term human milk until approximately 5 to 8 d postpartum. After that time, the GD3 concentration decreased sharply. In contrast, the total concentrations of GM3 per 1 mL of human milk from mothers after preterm delivery were lower than those from mothers after full-term delivery throughout the entire period examined.

Conclusion: This finding is essential to elucidate the composition of human milk gangliosides after preterm delivery, which may contribute to the analysis of the physiologic composition and formulation appropriate preterm infant nutrition.