Quantification of Helicobacter pylori infection: Simple and rapid ¹³C-urea breath test in Taiwan

The ¹³C-urea breath test (¹³C-UBT) is a noninvasive method for detecting Helicobacter pylori. This study was performed to determine the cutoff value and evaluate the sensitivity and specificity of ¹³C-UBT in Taiwan. ¹³C-Urea (100 mg of 99% ¹³C-labeled urea) was dissolved in 50 ml sterile water for the test. The test meal for delaying gastric emptying was 100 ml fresh milk. Patients fasted for at least 6 h. A baseline breath sample was collected 5 min after they had the test meal. Two other samples were collected at 15 and 30 min after the patients ingested the ¹³C-urea. The test was evaluated in 352 patients after routine upper gastrointestinal endoscopy, and the urease test, culture, and histopathology were taken as the gold standards for detecting H. pylori. According to the receiver operating characteristic (ROC) curves, we chose values of 2.8 and 4.2 excess δ ¹³CO₂ per mil as the cut-off values for 15 and 30 min, respectively, post ¹³C-urea. The sensitivity and specificity of ¹³C-UBT were 99% and 93% at 15 min, and 98% and 93% at 30 min post ¹³C-urea, respectively. The ¹³C-UBT breath test is an efficient non-invasive method of high sensitivity and high specificity for detecting H. pylori infection. We suggest that the use of fresh milk as the test meal and the detection of excess δ ¹³CO₂ 15 min after the ingestion of ¹³C-urea are suitable for the clinical use of ¹³C-UBT. This test is simple and rapid.