The urea breath test is a non-invasive diagnostic method used to evaluate Helicobacter pylori (H. pylori) infection, which is one of the important causes of stomach complaints. In this test, which can be performed without the need for endoscopy, breath samples taken from the patient are analyzed to assess whether the bacterium is actively present in the stomach. The urea breath test, which may be preferred based on physician evaluation in people with heartburn, indigestion, bloating, upper abdominal pain, and suspected gastritis or ulcer, can also be used to check whether the bacterium has been completely eradicated after treatment.
What Is the Urea Breath Test?
Helicobacter Pylori secretes a special enzyme called “urease” in order to survive in the gastric environment. The urea breath test helps evaluate whether the H. pylori bacterium is actively present by measuring the biological change caused by this enzyme.
Under normal conditions, urea in the stomach does not undergo any change. However, when H. pylori is present in the stomach, the urease enzyme secreted by the bacterium breaks down urea and causes the formation of ammonia and carbon dioxide. Thanks to a specially labeled carbon molecule used during the test, the carbon dioxide produced is expelled through the breath and measured with special analyzers to assess the presence of the bacterium. This method is one of the diagnostic techniques used to identify active infection.
Why Is the Urea Breath Test Performed?
The urea breath test can be used to investigate the cause of long-standing stomach complaints and to evaluate the effectiveness of the treatment applied. Whether the test is necessary is determined in line with the person’s complaints, medical history, and physician’s evaluation.
Evaluation of Helicobacter Pylori Infection
In people with heartburn, indigestion, bloating, upper abdominal pain, early satiety, and frequently recurring stomach complaints, H. pylori infection may be suspected. In this case, the urea breath test can help evaluate whether the bacterium is actively present.
In the Investigation of Gastritis and Peptic Ulcer
Helicobacter pylori is among the most important causes of chronic gastritis and stomach and duodenal ulcers. In patients suspected of having gastritis and peptic ulcer by the physician, the urea breath test may be requested to investigate whether there is an underlying H. pylori infection.
Checking the Success of H. pylori Treatment
It is important to evaluate whether the bacterium has been completely eradicated after treatment for H. pylori infection. Since the urea breath test is one of the methods that indicate active infection, it is preferred for assessing treatment success.
It May Help Prevent Unnecessary Drug Use
Long-lasting stomach complaints are not always caused by H. pylori infection. Similarly, not every stomach complaint requires the use of stomach-protective medications. The test, performed when deemed appropriate by the physician, may contribute to a more accurate evaluation of the cause of the complaints and to treatment planning based on scientific evidence.
How Is the Urea Breath Test Performed?
No endoscopic intervention, needle procedure, or surgical intervention is performed during the urea breath test. It can be completed in approximately 30–40 minutes, including preparation and waiting time.
The urea breath test consists of four basic steps: collection of the first breath sample, administration of the labeled urea solution, the waiting period, and collection of the second breath sample. The labeled urea solution used during the test interacts with the urease enzyme of Helicobacter pylori in the stomach. If the bacterium is present, the labeled carbon dioxide formed is expelled through the breath and evaluated by special analyzers.
How to Prepare Before the Test?
To obtain reliable results from the urea breath test, certain preparation rules must be followed before the procedure. Since the preparation period may vary depending on the medications used and the person’s health status, the physician’s recommendations before the procedure should be taken into consideration.
In general:
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You will be asked to fast for a certain period before the test.
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There is a specific waiting period after completion of antibiotic therapy.
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Since proton pump inhibitor (PPI) group stomach-protective drugs may affect the test result, they may need to be temporarily discontinued based on the physician’s recommendation.
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On the day of the test, not smoking and not chewing gum may be recommended.
The duration of discontinuation of medications may vary from person to person; stopping any medication should only be decided upon the physician’s recommendation.
The First Breath Sample Is Collected
When the procedure begins, the patient is asked to breathe normally into a specially prepared breath bag or analysis tube. This first sample is considered the baseline value and is later compared with the second sample.
The Labeled Urea Solution Is Administered
After the first sample is collected, the patient is given a special urea solution labeled with Carbon-13 (C13) to drink. In some applications, this substance may also be used in capsule form.
Since C13 is a natural, non-radioactive isotope of carbon, it does not cause exposure to ionizing radiation during the test.
Waiting Period
After taking the solution, a waiting period of about 15–30 minutes follows. During this time, if Helicobacter pylori is present in the stomach, the urease enzyme secreted by the bacterium breaks down the labeled urea and causes the formation of labeled carbon dioxide. The gas formed enters the bloodstream, reaches the lungs, and is expelled through the breath.
The Second Breath Sample Is Collected
After the waiting period is completed, the patient is asked to provide a second breath sample. The difference in the amount of labeled carbon dioxide between the first and second samples is evaluated by special analyzers.
The result obtained contributes to the physician’s clinical evaluation regarding whether the H. pylori bacterium is actively present.
How Long Does the Urea Breath Test Take?
While the administration of the test itself only takes a few minutes, the procedure is completed in an average of 30–40 minutes including the waiting period. After the procedure, the person can usually return to daily activities. When the test results will be ready may vary depending on the working schedule of the center where the test is performed.
How Are Urea Breath Test Results Evaluated?
The two breath samples taken during the procedure are analyzed in special devices. The change in the amount of labeled carbon dioxide between the first and second samples is evaluated to obtain information about the presence of Helicobacter pylori.
What Does a Positive Result Mean?
A positive urea breath test result may indicate that Helicobacter pylori is actively present in the stomach. In this case, clinical evaluation is performed in terms of stomach diseases that may be caused by the bacterium, and appropriate treatment can be planned if deemed necessary.
A positive test result does not always mean that there is a stomach ulcer or gastritis. The effects caused by the bacterium may vary from person to person.
What Does a Negative Result Mean?
A negative result indicates that no active urease enzyme activity attributable to Helicobacter pylori was detected during the test. This usually suggests that there is no active infection.
However, if the person’s complaints persist, it may be necessary to investigate other underlying stomach or digestive system diseases. Therefore, the test result must always be considered together with the clinical evaluation.
What Are the Advantages of the Urea Breath Test?
The urea breath test offers various advantages in terms of both the application process and the clinical information it provides. These advantages can be listed as follows:
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It is a non-invasive diagnostic method that does not require endoscopy.
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It can be performed without pain and without any surgical procedure.
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It helps actively evaluate Helicobacter pylori (H. pylori) infection.
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It can be used to assess whether the bacterium has been completely eradicated after treatment.
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It can be completed in an average of 30–40 minutes including preparation and waiting time.
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Most people can return to daily life after the procedure.
What Are the Risks and Side Effects of the Urea Breath Test?
The urea solution labeled with Carbon-13 (C13) used in the test is not radioactive. Therefore, it does not cause exposure to ionizing radiation. However, the suitability of the test should be determined by a specialist physician, taking into account the person’s age, general health status, special conditions such as pregnancy, and clinical evaluation.
Most patients do not experience any significant side effects during the procedure. Rarely, mild stomach discomfort, nausea, and changes in taste related to the solution may occur as temporary complaints. These symptoms usually resolve spontaneously within a short period of time.
No serious side effects are expected during the test, and the vast majority of patients can complete the procedure comfortably.
What Is the Difference Between the Urea Breath Test and Endoscopy?
The urea breath test and endoscopy are diagnostic methods used for different purposes. The urea breath test provides information about the presence of infection by evaluating the urease enzyme activity caused by Helicobacter pylori (H. pylori) in the stomach. Endoscopy, on the other hand, allows direct visualization of the esophagus, stomach, and duodenum. When necessary, it may also allow biopsy to be taken. Therefore, both methods are used for different clinical purposes.
