URINARY-EXCRETION OF LACTOSE AND OLIGOSACCHARIDES IN PRETERM INFANTS FED HUMAN-MILK OR INFANT FORMULA

At present. not much is known about the absorption and metabolism of h uman milk (HM) oligosaccharides in term and preterm infants. We invest igated the renal excretion of lactose and complex oligosaccharides in preterm infants fed HM (n=9, mean actual body weight 2290 g) or a cow' s milk-based infant formula (n=9, mean actual body weight 2470 g). We found that the renal excretion of lactose in HM-fed infants was slight ly lower than in formula-fed infants (14.0+/-7.4 versus 20.4+/-8.7 mg kg(-1) day(-1), mean+/-SD). The excretion of neutral sugars deriving f rom oligosaccharides was similar in HM-fed and formula-fed infants (3. 8+/-2.1 versus 2.9+/-0.9 mg kg(-1) day(-1)); the difference between me ans was not statistically significant. The separation and characteriza tion of oligosaccharides by high-pH anion exchange chromatography with pulsed amperometric detection (HPAE-PAD) and subsequent analysis by f ast atom bombardment-mass spectrometry (FAB-MS) revealed a more comple x pattern in HM-fed infants compared to the formula-fed group. Lactose -derived oligosaccharides characteristic for HM (e.g. lacto-N-tetraose , and lacto-N-fucopentaoses I and II) were excreted in HM-fed but nut in formula-fed infants. These results indicate that nutrition has a si gnificant impact on the oligosaccharide composition in urine of preter m infants.