¹³C-ethanol breath test reveals impaired alcohol metabolism in patients with Helicobacter pylori infection

Background: The gastric mucosal alcohol dehydrogenase activity was reported to be reduced in subjects with Helicobacter pylori-associated chronic gastritis. However, the role of H. pylori infection in the metabolism of ingested ethanol has not been fully elucidated. Aim: To clarify whether H. pylori infection exerts any influence on the metabolism of small amounts of ethanol in humans. Subjects and methods: ¹³C-ethanol (100 μL) diluted in 100 mL water was administered orally to 22 healthy volunteers before breakfast. Breath samples were then collected every 10 min for up to 60 min. The content of ¹³CO₂ (‰) was analysed using a mass-spectrometric method. The excretion rate of labelled CO₂ was analysed by calculation of the following mathematical parameters, i.e., T _max, C_max, and AUC₆₀. Results: In H. pylori-negative controls (n = 11), the T_max, C_max and AUC₆₀ were 0.47 ± 0.13, 19.1 ± 6.0 and 13.7 ± 4.5, respectively. The corresponding values were 0.53 ± 0.16 (n.s.) and 12.7 ± 4.8 (P < 0.05) and 9.0 ± 3.6 (P < 0.05), respectively, in subjects with H. pylori infection (n = 11). Successful eradication of H. pylori was associated with significant increase of these parameters (C_max and AUC₆₀, n = 6). Conclusions: The metabolism of small amounts of ethanol is attenuated in subjects with H. pylori infection.