[¹³C] Breath Test of Medium‐chain Triglycerides and Oligosaccharides in Neonates

It is suitable to examine the utilization of carbohydrates and fats using stable isotope‐labelled substrates in neonates because of their non‐radioactivity. Administering medium‐chain triglycerides (MCT) and oligosaccharides is of use in enteral nutrition for a patient with a limited water intake such as a neonate. In this study, the oxidation of MCT and maltose administered orally as an energy supplement in neonates has been examined using a stable isotope‐labelled breath test. Five normal term neonates and five growing preterm infants were given [¹³C]‐trioctanoin orally and three growing preterm infants were given [¹³C]‐glucose and [¹³C]‐maltose orally. The [¹³C] enrichment in carbon dioxide was analyzed by isotope ratio mass spectrometry, and oxidation rates over 6 hr and 12 hr respectively, were calculated. The oxidation rates for [¹³C]‐octanoin after 6 hr were 46.2 ± 3.6% in preterm infants and 53.5 ± 13.8% in normal neonates, respectively (no significant difference), and 58.4 ± 9.4% and 52.8 ± 6.0% for [¹³C]‐glucose and [¹³C]‐maltose, respectively (not significant). The results demonstrate that orally administered MCT and maltose are oxidized sufficiently in preterm infants.