The following table provides an overview of which breath tests are used for which questions. Not all tests are paid for by statutory health insurance – talk to your doctor.
13C-breath tests
Primarily, dysfunctions in the stomach can be identified; used to monitor therapy for infections with Helicobacter pylori (initial diagnosis is made using a biopsy obtained during endoscopy); also used for diagnostic purposes in children. 13C-octanoic acid or 13C-acetate breath test Diagnosis and follow-up of gastric emptying disorders, especially gastric paralysis (gastroparesis); testing of the efficacy of certain drugs that promote gastric motility.
H2 breath tests
Disturbances in the digestion of certain food components in the small intestine and its bacterial overgrowth can be detected. It is also possible to determine the time it takes for the food mush to pass through the small intestine. Therefore, these tests are used in patients with digestive disorders such as diarrhea, flatulence and nausea.
Lactose H2 breath test Performed in cases of unclear diarrhea or flatulence, especially when lactose intolerance is suspected. In this case, an enzyme is missing in the small intestine with which the lactose (milk sugar) is split. Therefore it cannot be absorbed, reaches the large intestine and is decomposed there by the intestinal bacteria. This leads to the abdominal pain, flatulence and diarrhea. The disorder – which is harmless – is widespread in Western Europe, affecting 10-15% of people, and improves with an appropriate (low-lactose) diet.
Fructose H2 breath test Performed in cases of unclear diarrhea, flatulence, air in the abdomen, bloating, nausea and other uncharacteristic abdominal complaints, especially if fructose intolerance is suspected. Fructose (fruit sugar) is a common component of our diet, found in table sugar, fruit and honey. In some people, absorption from the small intestine is reduced due to a poorly functioning transport mechanism. As with lactulose intolerance, the fructose then reaches the large intestine and causes discomfort. Here, too, an appropriate diet helps.
Sucrose H2 breath test Performed as a supplement to the lactose test if the latter is borderline and it is suspected that not only the digestion of lactose but that of all double sugars (disaccharides) is disturbed.
Glucose H2 breath test Normally, glucose (dextrose) is completely absorbed in the small intestine. If bacteria have settled there, they convert part of the glucose into hydrogen beforehand, which can be measured in the test. The symptoms of bacterial overgrowth (e.g. as a result of antibiotic therapy) are non-specific, and include in particular diarrhea, flatulence and a feeling of fullness after eating.
Xylose H2 breath test It is used in a similar way to the lactose test. It shows non-specific pathological values in all absorption disorders in the upper gastrointestinal tract.
Lactulose H2 breath test Since lactulose is not absorbed, it always migrates to the large intestine, even in healthy people, where it is decomposed by bacteria to (hydrogen) H2. However, in as many as 10% of the population, the intestinal flora does not produce hydrogen. This test is primarily used to filter out such people, since H2 tests are not meaningful for them. It can also be used to determine the passage time through the small intestine.
