¹³C-breath tests: Current state of the art and future directions

Abstract 

¹³C-breath tests provide a non-invasive diagnostic method with high patient acceptance. In vivo, human and also bacterial enzyme activities, organ functions and transport processes can be assessed semiquantitatively using breath tests. As the samples can directly be analysed using non-dispersive isotope selective infrared spectrometers or sent to analytical centres by normal mail breath tests can be easily performed also in primary care settings.

The ¹³C-urea breath test which detects a Helicobacter pylori infection of the stomach is the most prominent application of stable isotopes. Determination of gastric emptying using test meals labelled with ¹³C-octanoic or ¹³C-acetic acid provide reliable results compared to scintigraphy. The clinical use of ¹³C-breath tests for the diagnosis of exocrine pancreatic insufficiency is still limited due to expensive substrates and long test periods with many samples. However, the quantification of liver function using hepatically metabolised ¹³C-substrates is clinically helpful in special indications. The stable isotope technique presents an elegant, non-invasive diagnostic tool promising further options of clinical applications.

This review is aimed at providing an overview on the relevant clinical applications of ¹³C-breath tests.

Keywords: Gastric emptying, Helicobacter pylori, Liver function, Stable isotopes