Breath hydrogen response to lactose in Chinese neonates

Abstract

Breath hydrogen response to oral lactose was studied in 89 neonates of Chinese origin, 54 term and 35 preterm. End-expiratory air samples were collected with an automatic electronic device newly developed by the authors. Breath H2 was analyzed with Shimadzu gas chromatograph. Post-lactose rise in breath H2 of 20 ppm appears to distinguish two populations of infants, namely the lactose-absorbers with lower rises and the mal-absorbers with higher rises. Preterm infants showed much higher frequency of lactose mal-absorption as indicated by excessively high breath H2 response, a feature compatible with immature lactase development. Although given similar amount of lactose for the test, infants taking formula showed significantly lower breath H2 response than taking freshly prepared lactose solution. Slower gastric emptying with formula may be a reason for the difference. 97% of healthy term infants and 92% of healthy preterm neonates showed no evidence of lactose-malabsorption when fed the usual 7%-lactose-containing formula by the breath H2 response test.