Evaluation of alcohol metabolism in humans using the non-invasive [ 13C]-ethanol breath test - Influence of gender, Helicobacter pylori infection and polymorphism of alcohol-oxidizing enzymes

Summary Background The [13C]-ethanol breath test (EBT) has been proposed as a novel non-invasive laboratory test to detect the degradation of ethanol into CO2. However, this method has not yet been evaluated clinically. Aim To investigate the factors that influence [13C]-EBT. Methods Twenty-six healthy volunteers were instructed to drink 100 mL of beer (4 g ethanol) containing 100 μL of [13C]-ethanol. Breath samples were collected every 15 min before and after the intake of ethanol solution and 13CO2-enrichment was measured using mass spectrometry. CO2 excretion was then calculated, and the results were evaluated using kinetic parameters (Tmax, Cmax, AUC). Results Tmax (min) was significantly shorter in men than in women but not Cmax and AUC. Infection with H. pylori had no impact on all kinetic parameters. Genetic alcohol dehydrogenase (ADH) polymorphisms did not affect 13CO2 excretion, but Cmax (11.1 ± 3.4% dose/h, n = 16) and AUC (10.5 ± 3.4% dose) were slightly increased in aldehyde dehydrogenase (ALDH)-deficient individuals (heterozygote of ALDH2*2) (13.2 ± 3.2 and 12.9 ± 4.5, respectively; n = 10). Conclusions [13C]-EBT is capable of assessing the metabolic processing of 100 mL beer in a non-invasive way. Kinetic parameters are partially influenced by ALDH polymorphism but not by gender, H. pylori infection or ADH polymorphism.