Galactosyllactoses in the Milk of Japanese Women: Changes in Concentration during the Course of Lactation

Abstract

The concentrations of three galactosyllactoses found in the milk of 24 Japanese women were determined using normal phase high-performance liquid chromatography of the 2-aminopyridyl (PA) derivatives of the oligosaccharides. The milk was collected at 4, 10, 30 and 100 days post partum. The concentration of 6'-galactosyllactose (6'-GL) was maximal at 4 days post partum, and then decreased, whereas the concentrations of 3'- and 4'-galactosyllactose (3'-GL and 4'-GL) did not change during the course of lactation. In human milk, 6'-GL was the main oligosaccharide among these galactosyllactoses at 4 days post partum, in contrast to bovine milk in which 3'-GL has been reported to be predominant. The concentrations of these galactosyllactoses in human milk were much lower than those reported for 2'-fucosyllacose, 3-fucosyllactose, lacto-N-fucopentaose I, II and III, and 3'- and 6'-N-acetylneuraminyllactose. (author abst.)