Applications of Stable Isotopes to Pediatric Nutrition and Gastroenterology

Background:For indirect evaluation of pancreatic lipase activity in cystic fibrosis, different 13C‐labeled triglycerides may be used.Methods:Triglyceride oxidation in patients with cystic fibrosis was investigated after administration of different 13C‐labeled triglycerides by comparing 13CO2 breath exhalation. In the comparative study, five patients with cystic fibrosis (age, 8‐15 years; body weight, 22.5‐39.8 kg) were treated with Pangrol (individual dosages: 1‐3 capsules per morning meal; Berlin‐Chemie, Berlin, Germany). [1,1,1‐13C3]Glyceryl tripalmitate and [1,1,1‐13C3]glyceryl trioleate were administered as a single oral pulse at 8:00 A.M. (dosage, 4 mg/kg each) with the standard diet Fresubin (dosage, 10 ml/kg; Fresenius, Bad Homburg, Germany). Alternately, the same subjects were given the synthetic mixed triglyceride 1,3‐distearyl, 2[13C]octanoyl glycerol (dosage, 12.5 mg/kg) contained in the standard diet Nutri‐Mix (dosage, 10 ml/kg; Nutricia, Zoetemeer, The Netherlands). Breath samples were taken in 15‐ and 30‐minute intervals over 8 hours. The 13CO2 enrichment was measured by continuous‐flow isotope ratio mass spectrometry.Results:After administration of the 13C‐labeled tripalmitin‐triolein mixture and the mixed triglyceride, mean maximum 13CO2 enrichments were 4.70 and 7.37 δ over baseline, occurring at 7.0 and 3.5 hours, respectively. The corresponding percentage cumulative 13CO2 exhalations were 12.25% and 29.19%, respectively, and differed significantly in the five paired subjects (p = 0.003).Conclusions:After using different 13C‐labeled triglycerides the resultant 13CO2 exhalation reflected the triglyceride hydrolysis and subsequent oxidation. It is concluded that the different cumulative 13CO2 exhalations were mainly caused by the rate‐limiting step of triglyceride hydrolysis to free fatty acids and 2‐monoglycerides and by fat deposition. Noninvasive 13C breath tests using different 13C‐labeled triglycerides can be used for evaluation of pancreatic lipase activity before and during enzyme supplementation.

Triglyceride Oxidation in Cystic Fibrosis: A Comparison Between Different ¹³C‐Labeled Tracer Substances

Wutzke,

Radke,

Breuel

et al. 1999

Stable Isotope Techniques for the Assessment of Host and Microbiota Response During Gastrointestinal Dysfunction

Butler

Kosek

Krebs

et al. 2017

The International Atomic Energy Agency convened a technical meeting on environmental enteric dysfunction (EED) in Vienna (October 28-30, 2015; https://nucleus.iaea.org/HHW/Nutrition/EED_Technical_Meeting/index.html) to bring together international experts in the fields of EED, nutrition, and stable isotope technologies. Advances in stable isotope-labeling techniques open up new possibilities to improve our understanding of gastrointestinal dysfunction and the role of the microbiota in host health. In the context of EED, little is known about the role gut dysfunction may play in macro- and micronutrient bioavailability and requirements and what the consequences may be for nutritional status and linear growth. Stable isotope labeling techniques have been used to assess intestinal mucosal injury and barrier function, carbohydrate digestion and fermentation, protein-derived amino acid bioavailability and requirements, micronutrient bioavailability and to track microbe-microbe and microbe-host interactions at the single cell level. The noninvasive nature of stable isotope technologies potentially allow for low-hazard, field-deployable tests of gut dysfunction that are applicable across all age groups. The purpose of this review is to assess the state-of-the-art use of stable isotope technologies and to provide a perspective on where these technologies can be exploited to further our understanding of gut dysfunction in EED.

¹³C‐Labeled‐Starch Breath Test in Congenital Sucrase‐isomaltase Deficiency

Robayo–Torres

Diaz-Sotomayor

Hamaker

et al. 2018