Definition of Urea breath test (UBT)
Urea breath test (UBT): The urea breath test (UBT) is a
procedure for diagnosing the
presence of a
bacterium, Helicobacter pylori (H. pylori) that causes inflammation,
ulcers,
and atrophy of the stomach. The test also may be used to demonstrate
that
H. pylori has been eliminated by treatment with antibiotics.
The urea breath test is based on the ability of H. pylori to break
down
urea, a chemical made of nitrogen and carbon, that normally is
produced by the
body from excess ("waste") nitrogen and then eliminated in the urine.
For
the test, patients swallow a capsule containing urea made from an
isotope
of carbon. (Isotopes of carbon occur in minuscule amounts in nature,
and can
be measured with special testing machines.) If H. pylori is present
in the
stomach, the urea is broken up into nitrogen and carbon (as carbon
dioxide).
The carbon dioxide is absorbed across the lining of the stomach and
into the
blood. It then is excreted from the lungs in the breath. Samples of
exhaled breath are collected, and the isotopic carbon in the exhaled
carbon
dioxide is measured.
If the isotope is detected in the breath, it
means that H.
pylori is present in the stomach. If the isotope is not found, H.
pylori
is not present. When the H. pylori is effectively treated
(eradicated) by
antibiotics, the test changes from positive (isotope present) to
negative
(isotope absent).
Last Editorial Review: 12/13/1998
- Endoscopy (Esophagogastroduodenoscopy, EGD) - Learn about the endoscopy procedure which examines the esophagus, stomach and duodenum to detect gastrointestinal and digestive disorders on MedicineNet.com
- Stomach Cancer - Read about stomach cancer symptoms, causes, stages, gastric cancer statistics, diagnosis, surgery, other treatment types and risk factors, like H. pylori.
- Peptic Ulcer - Learn about peptic ulcers, a hole in the gut lining of the stomach, duodenum, or esophagus.
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