What is the purpose of the hydrogen breath test?

The hydrogen breath test is a diagnostic procedure that helps diagnose gastrointestinal issues such as lactose intolerance, fructose intolerance, and small intestinal bacterial overgrowth (SIBO). Digestive disorders are becoming increasingly common, and many people may experience uncomfortable symptoms such as bloating, abdominal pain, or diarrhea. These complaints are often related to an imbalance in gut flora or malabsorption of nutrients.

During the test, the amount of hydrogen exhaled by the patient is measured, which indicates fermentation processes occurring in the intestines. If the gut flora is not functioning properly, nutrients such as lactose or fructose are not digested adequately, leading to hydrogen production. The aim of the test is to identify the foods or components that cause the patient’s complaints.

Diagnosing digestive disorders is not only about alleviating symptoms but also allows for the introduction of appropriate dietary changes. An accurate diagnosis can help patients avoid foods that cause problems for them, thereby improving their quality of life.

What should be considered before the test?

Preparing for the hydrogen breath test is essential for accurate results. In the week leading up to the test, it is important for the patient to avoid certain medications. These include laxatives, stool softeners, proton pump inhibitors, antibiotics, and probiotics. These substances can affect the composition of gut flora and distort the test results.

Particular attention should also be paid to diet the night before. Hard-to-digest foods, such as fatty foods, fibrous plants, or gas-producing foods like potatoes, rice, and pasta, should be avoided. The test should be conducted on an empty stomach, meaning that the last meal should be completed at least six hours before the test. For the last six hours, neither eating nor drinking is allowed, and no medications can be taken.

Additionally, brushing teeth and smoking should be avoided for twelve hours before the test, as these can also affect the composition of exhaled air. Rinsing the mouth with tap water is permitted, but swallowing is prohibited. Proper preparation is crucial for the test to yield reliable results.

How does the test procedure work?

The hydrogen breath test consists of several steps. First, the patient’s mouth and throat are rinsed with an antibacterial solution, which helps minimize the impact of bacteria in the mouth during the test. The patient then consumes 300 ml of liquid, which may contain lactulose, lactose, or fructose, depending on which intolerance is being tested.

After consuming the liquid, the patient breathes into a device used for testing, which measures the hydrogen concentration in the exhaled air every 20 minutes. The total duration of the test is approximately 120-180 minutes, and the measurements are evaluated relative to the baseline value. During the test, it is also important to monitor for symptoms characteristic of lactose or fructose intolerance, such as abdominal cramps, nausea, bloating, or diarrhea.

During the evaluation of the results, specialists analyze the changes in measured hydrogen concentration. An elevated hydrogen level compared to normal values may indicate lactose or fructose intolerance, while normal values suggest that the gut flora is functioning healthily.

The scientific background of the test

The scientific basis of the hydrogen breath test lies in the functioning of gut bacteria. The test with lactulose allows for the detection of bacteria overgrowth in the small intestine. Normally, lactulose is only fermented in the large intestine; however, if bacteria are abnormally proliferating in the small intestine, lactulose begins to ferment earlier. This process leads to hydrogen production, which can be measured in the exhaled air.

In the lactose test, the role of the lactase enzyme is to break down lactose into glucose and galactose. If the activity of the lactase enzyme is reduced or absent, lactose is not digested properly, which also results in hydrogen production. During the test, an increase in hydrogen levels above 20 ppm is considered a sign of lactose intolerance.

In the case of fructose intolerance, fructose is not absorbed properly in the small intestine, leading to fermentation in the large intestine, which also results in hydrogen production. A positive result during the test indicates that the patient suffers from fructose intolerance.

The hydrogen breath test is conducted in healthcare centers equipped with specialized instruments. With the results in hand, specialists can recommend appropriate dietary changes, such as the introduction of a lactose-free or fructose-free diet. In cases of small intestinal bacterial overgrowth, antibiotic treatment may also become necessary.