The presence of active Helicobacter pylori (H.p) infection can be diagnosed non-invasively with the C-14 urea breath test (UBT). This test is based on the detection of the enzyme urease, produced by Helicobacter pylori. Since urease is not present in normal human tissues, and since other urease-producing bacteria do not colonize the stomach, the presence of urease in the stomach can be equated with Helicobacter pylori infection.
﹛In the presence of urease, orally administered C-14 urea will be hydrolyzed into ammonia and 14CO2. 14CO2 is absorbed into the circulation and exhaled by the lungs. The presence of a significant amount of 14CO2 in the exhaled breath indicates active Helicobacter pylori infection.