Comparison of different protocols for 13C-urea breath test for the diagnosis of Helicobacter pylori infection in healthy volunteers

Objective. The C-13-urea breath test (C-13-UBT) is the most accurate non-invasive method for diagnosis of Helicobacter pylori infection. However, several methodological issues have not been resolved yet. The aim of this study was to test different protocols of C-13-UBT to find the optimal test drink and sampling interval. Material and methods. C-13-UBT was performed at 3-day intervals in 27 healthy volunteers using citric acid ( test A), orange juice ( B) and still water ( C) as test drinks. Breath samples were collected from time 5 to 60 min. A total number of 2106 breath samples were analysed by isotope ratio mass spectrometry ( cut-off value 3.5). Results. Differences in delta values were greater than would be expected by chance ( A versus B and A versus C at times 20, 25, 30, 35 and 40 min, p<0.05, Dunnett's method). There were no grey zone-or false-negative results among H. pylori-positive persons in test A at any time, but some were found in tests B and C. Optimal intervals for breath sampling are at times 20 or 25 min after C-13-urea ingestion. Conclusions. Citric acid solution as a test drink and 20- or 25-min breath sampling intervals are optimal for the C-13-UBT in healthy volunteers.