Diurnal variations and within the feed in lactose and oligosaccharides of human milk.

Variations of lactose and oligosaccharides in human milk were studied during the day and the feed, by dialysis, chromatography on Bio-gel P-2 column, paper chromatography, colorimetric analysis and gas chromatography. Progressive changes were found during the day, but not during the feed. A diurnal variation in milk lactose was seen, which was the inverse of the oligosaccharides. Significant negative correlations between lactose and oligosaccharides were seen in the afternoon and evening (p less than 0.05). The minimal mean value of lactose at 19.00 h is 58.64 +/- 5.28 g/l and the maximal mean values of oligosaccharides was 17.93 +/- 2.28 g/l. The data are discussed with regard to other milk constituents and to their possible physiological relevance.