Gastric Emptying in Formula‐Fed and Breast‐Fed Infants Measured with the 13 C‐Octanoic Acid Breath Test

• Published in: Journal of pediatric gastroenterology and nutrition Vol. 29; no. 1; pp. 46 - 51
• Main Authors: Van Den Driessche, Mieke, Peeters, Kristel, Marien, Paul, Ghoos, Yvo, Devlieger, Hugo, Veereman‐Wauters, Gigi
• Format: Journal Article
• Language: English
• Published: 01.07.1999
• ISSN: 0277-2116; 1536-4801
• DOI: 10.1002/j.1536-4801.1999.tb02360.x

ABSTRACT Background: The 13 C‐octanoic acid breath test, a noninvasive method for measuring gastric emptying, was used to compare the gastric‐emptying rate of formula‐fed and breast‐fed infants. Octanoic acid, a medium‐chain fatty acid marked with the stable isotope 13 C is immediately absorbed in the duodenum. Because gastric emptying is the rate‐limiting step for the absorption of medium‐chain fatty acids, the fraction of 13 C expired in the breath indicates the rate of gastric emptying. Methods: Twenty‐nine newborn infants (16 boys, 13 girls) were investigated, with parental consent. The infants had a mean gestational age at birth of 34.5 weeks (range, 27‐41 weeks) and a birth weight of 2148 g (range, 960‐4100 g). Their mean weight on the day of the test was 2496 g (range, 1998‐4140 g), and their mean age was 23 days (range, 7‐74 days). Each infant received a test meal after a maximum fasting period of 3 hours. Fourteen infants were fed formula milk (Nutrilon Premium, NV Nutricia, Zoetermeer, The Netherlands) with 13 C‐octanoic acid and 15 infants received expressed mother's milk mixed with 13 C‐octanoic acid. After obtaining two basal breath samples and the feeding, breath samples were collected using a nasal prong, every 5 minutes during the first half hour and every 15 minutes during the next 3.5 hours. Analysis of the expired 13 C fraction in the breath samples was performed using isotope‐ratio mass spectrometry, and the gastric emptying curve and gastric emptying parameters were determined. Results: The mean half‐emptying time determined by the 13 C‐octanoic acid breath test was 65 minutes (range, 27‐98 minutes) for the formula fed infants and 47 minutes (range, 16‐86 minutes) for the breast‐fed infants. The difference between the half‐emptying times is significant ( t ‐test, p < 0.05). Conclusions: The results of the 13 C‐octanoic acid breath test indicated faster gastric emptying of human milk than formula. Our findings are in accordance with those in earlier studies, using the invasive‐dilution technique; noninvasive and detailed ultrasonography, which is not easily used because it is operator dependent and the observation time is short; or cineesophagogastroscintigraphy, which is less suitable for infants (because of the radiation involved). The 13 C‐octanoic acid breath test is a safe and noninvasive method for measuring gastric emptying in small infants and allows comparison of various feeding methods.