[13C-urea breath test as a non-invasive method for the detection of Helicobacter (Campylobacter) pylori]

The 13C-urea breath test was used for diagnosing noninvasively the possible presence of Helicobacter (formerly called Campylobacter) pylori in 20 patients with dyspepsia (ten men and ten women, mean age 40.2 [24-74] years). H. pylori was cultured from 14 patients, while in six the culture was negative. The proportion of 13C in expired air was measured by isotope mass-spectrometer and expressed as Delta (basal value about 20%). A dose of 2.5 mg urea per kg body-weight (BW) was ingested after a standard meal. The test was repeated with 1.75 and 1.0 mg/kg BW in five subjects. Delta had increased significantly after 30 min in all H. pylori-positive patients (P less than 0.001). The maximal value after 90 min ranged from 38 to 114%; in the H. pylori-negative patients it was 24%. After 1.75 and 1.0 mg/kg urea the maximal value after 90 min was 39-52% and 30-52%, respectively. Using a dose of 2.5 or 1.75 mg/kg BW tagged urea one can reliably distinguish between presence and absence of H. pylori. It is sufficient to test a basal and a 90-min expired-air sample.