The oligosaccharide composition of human milk: temporal and individual variations in monosaccharide components

J Pediatr Gastroenterol Nutr. 1994 Nov;19(4):371-6. doi: 10.1097/00005176-199411000-00001.


Oligosaccharides are an important component of human milk, but little is known about variations in their composition. The aim of this study was to determine the temporal and inter-individual variations in carbohydrate composition of human milk during the first 3 months of lactation. Serial milk samples of 10 mothers (eight full-term and two preterm births) were analyzed to determine the concentration of lactose and three monosaccharide components derived from the non-lactose carbohydrate: sialic acid, N-acetylglucosamine, and fucose. In full-term milk, sialic acid and N-acetylglucosamine were found to decrease significantly (p < 0.05) from weeks 1 to 13 postnatally. On average (mean +/- SD), sialic acid decreased by 71% (from 879 +/- 157 to 256 +/- 82 mg/L; p < 0.05) and N-acetylglucosamine by 56% (from 1,459 +/- 282 to 646 +/- 214 mg/L; p < 0.05), while fucose decreased by only 35% (from 660 +/- 192 to 432 +/- 180 mg/L; p > 0.05). On average, lactose concentration increased by 17% over the same period, from 55.4 +/- 4.2 g/L in week 1 to 64.9 +/- 2.3 g/L at 3 months. Preterm milk contained higher concentrations of each component, but temporal changes were similar to those seen in full-term milk. Apart from temporal changes, there were large inter-individual differences in oligosaccharide composition: fucose varied four-fold, sialic acid threefold, and N-acetylglucosamine two-fold among women at the same stage of lactation. The changes observed may simply reflect the aging of the cells responsible for milk secretion, but they are also consistent with a programmed adaptation of the milk composition to the needs of the infant.

MeSH terms

  • Acetylglucosamine / analysis*
  • Analysis of Variance
  • Female
  • Fucose / analysis*
  • Humans
  • Lactose / analysis*
  • Milk, Human / chemistry*
  • N-Acetylneuraminic Acid
  • Obstetric Labor, Premature
  • Pregnancy
  • Sialic Acids / analysis*
  • Time Factors


  • Sialic Acids
  • Fucose
  • N-Acetylneuraminic Acid
  • Lactose
  • Acetylglucosamine