Changes of gangliosides and sialic acid in human milk during lactation

Abstract

To elucidate the possible biological function of gangliosides in human milk, the content and composition of gangliosides in human milk during lactation were examined. Gangliosides were rich in human milk at the earlier stages of lactation. The major ganglioside was GD3. The content of GD3 decreased, while that of GM3 increased in the later stages of lactation. GD1a, and polysialogangliosides were rich in the milk at 6 days of postpartum. Levels of sialic acid and sialidase, a ganglioside-hydrolyzing enzyme, were also studied. The content of sialic acid and sialidase activity were decreased in the later stages of lactation. As the results, GD3, GD1a, polysialogangliosides, sialic acids (lipid-bound and protein-bound), and sialidase were rich in human colostrum and these components may play a role in immune system.