Starch Digestion in Young Children with Cystic Fibrosis Measured Using a 13C Breath Test

Abstract

ABSTRACT. The study was designed to evaluate a noninvasive breath test using naturally I3C-rich corn (maize) as substrate to provide quantitative information about the digestion of starch by children in health and disease. The variability of background I3C:l2C of young British children was investigated by collecting breath samples over 6 h from 17 healthy children, 6-35 mo old, and from seven children with cystic fibrosis, 25-48 mo old, in their homes. Children with cystic fibrosis have decreased activity of pancreatic amylase (I), the major enzyme involved in the intraluminal hydrolysis of starch. As a consequence, most children with cystic fibrosis receive pancreatic enzyme supplements containing a-amylase (2). Although starch is the principal complex carbohydrate in the diet during early life and represents about 20% of the total energy intake at 2 y of age in children in Europe (3,4), information about the digestion of this carbohydrate in young children with cystic fibrosis is limited (5). In addition, the effect of enzyme supplements on the digestion of starch has not been clearly established in children.Noninvasive breath tests, which involve substrates that are naturally or artificially labeled with I3C, the stable isotope of carbon, have been used to make quantitative measurements of the digestion of complex carbohydrates in healthy infants and adults (6,7) and in those with pancreatic insufficiency (8). When

Feasibility of a breath test with a substrate of natural 13C‐abundance and isotope‐selective non‐dispersive infrared spectrometry: A preliminary study

“…Depending on the type of the substrate administered orally, it is possible to evaluate the pancreatic lipase, 17 trypsin, 18 or amylase activity. [5][6][7][8][9] Remarkably, an exact functional relationship between the cumulative 13 CO 2 recovery in the exhaled air and intrajejunal activity of a pancreatic enzyme pertinent to the ingested substrate was established. 5,17,18 Among validated so far variants of 13 C pancreatic function breath tests, the examination with the use of a synthetically obtained 13 C-mixed triglyceride gained the most popularity.…”

“…This approach resulted, however, in a high between-subject variability in the amount of ingested starch, which fluctuated within a range of 0.2-2.8 g/kg body mass. 6 A prerequisite for valid measurements of 13 CO 2 increment after intake of a substrate of a natural origin is a low basal or background 13 C content in the expiratory air. Because of the different dietary habits, the breath of Europeans contains significantly less 13 CO 2 (-19.8 to -24.3 d‰ PDB) than that of Americans (-16.4 to -21.0 d‰ PDB).…”

“…Convincing evidence about applicability of corn starch for the assessment of pancreatic exocrine function was given by researchers who used the IRMS for the determination of 13 CO 2 in the exhaled air. [5][6][7][8][9] The aim of this study was threefold: (i) to establish if NDIRS is sensitive enough to reliably measure 13 CO 2 concentration in breath samples after ingestion of a substrate with natural abundance of 13 C; (ii) to determine the dose of such a substrate, which would provide a sufficient postingestion increase in 13 CO 2 ; and finally (iii) to check, among a large group of healthy subjects consuming a test breakfast containing the natural substrate, the variability of 13 C recovery relative do the administered dose.…”

Is there an advantage in normalising the results of theHelicobacter Pylori[13C]Urea breath test for CO2production rate in children?

“…We have previously used the Shreeve method [6], which assumes a constant value of 300 mmol CO 2 =h m 2 body surface [8][9][10][11] to estimate CO 2 production rate during 13 C breath tests. Alternatively, BMR can be estimated using the Schofield equations [12], which are generally agreed to give a more accurate estimate in children [13].…”

Improving the specificity of the [13C]mixed triacylglycerol breath test by estimating carbon dioxide production from heart rate

“…These include tests of starch digestion and fermentation (Dewit et al, 1992;Weaver et al, 1995;Christian et al, 2003) and liver function tests (Parker et al, 1994(Parker et al, , 1997(Parker et al, , 1998). …”