Letzte Aktualisierung am 9. September 2024 von Dr. Michael Zechmann-Khreis
The hydrogen breath test or H2 breath test helps to detect intolerances to lactose(lactose intolerance), fructose(fructose malabsorption) or sorbitol (sorbitol intolerance). It can also be used to diagnose bacterial overgrowth in the small intestine.
Table of the most common breath tests
| Diagnose der | Testsubstanz | Menge | Pust-Intervall | Dauer des Tests |
|---|---|---|---|---|
| Laktoseintoleranz | Laktose | 25-50g | 15 oder 30 min | 2 Stunden* |
| Fruktoseintoleranz | Fruktose | 25g | 15 oder 30 min | 2 Stunden* |
| DDFB | Glukose | 50g | 10-20 min | 3 Stunden |
| DDFB | Laktulose | 10g | 10-20 min | 3 Stunden |
| Sorbitintoleranz | Sorbit | 5-12g | ca. 20 min | 3 Stunden |
| * Sind die Werte nach 2 Stunden maximal 10-20 ppm über den Basalwert gestiegen, sollte der Test auf 4 Stunden verlängert werden. | ||||
Explanations for image1):
The gray line shows a test person who does not have fructose intolerance.
It should be noted that the measurement with 4 measuring points (yellow line) in comparison to the frequent measurement (orange line) diagnoses intestinal fructose intolerance, but cannot make any statement about small intestine overgrowth (DDFB).
The blue line shows a test subject with fructose intolerance but without DDFB.
H2 breath test for small intestine colonization
As mentioned in this article, you can also use the fructose breath test to diagnose small bowel dysbiosis (DDFB). So if you take a fructose breath test, you can kill two birds with one stone. However, there are two other test substances that are suitable for this purpose: Lactulose and glucose.
With lactulose: If the value after 90 minutes has already risen by more than 20 ppm or is higher than the values after 120 or 180 minutes, a small intestine overgrowth can be assumed.
With glucose: An increase of more than 20 ppm from the initial value is generally considered a positive finding. Glucose is absorbed very quickly and often does not even reach the posterior sections of the small intestine, which is why the lactulose test should be preferred for the diagnosis of DDFB.
Problems with H2 breath tests
Around 10 % of the population are non-H2 producers. They have bacteria that immediately metabolize the hydrogen produced. As a result, it does not get into the breath and therefore cannot be measured. However, as the diagnosis is also based on the symptoms, these patients can also be diagnosed. If severe symptoms occur during the course of the day, the test is also positive despite the hydrogen levels in the breath not increasing. This is why it is so important to document the symptoms on that day and, if necessary, report them to the doctor immediately. Actually, in addition to hydrogen, methane should also be measured in the breath, as this allows non-responders to be identified. However, as these test devices are more expensive, these tests are very rarely carried out in practice.
If possible, your doctor should carry out a blood test to determine other blood values (in the case of fructose intolerance, these are primarily folic acid, B12, serum amylase, lipase, zinc and iron).
Do H2 home tests work?
Breath H2 samples remain stable at room temperature for up to six hours. If longer storage is required, the samples should be stored at -20 °C, as approximately one third of the hydrogen escapes from the container within a few days2). Due to this limitation, home testing by mail is not recommended.
Sources:
1) Zechmann-Khreis, M., own figure
2) Corazza, G. R. et al. Methodology of the H2 breath test.
I. Collection and storage for gas measurement. Ital.
J. Gastroenterol. 22, 200-204 (1990).
3) Satish S.C. Rao, Ashok Attaluri, Leslie Anderson, Phyllis Stumbo; “Ability of the Normal Human Small Intestine to Absorb Fructose: Evaluation by Breath Testing”; Clinical Gastroenterology and Hepatology 2007;5:959-963
4) Mastropaolo, G., & Rees, W. D. (1987). Evaluation of the hydrogen breath test in man: definition and elimination of the early hydrogen peak. Gut, 28(6), 721-5.
5) Simrén, M., & Stotzer, P.-O. (2006). Use and abuse of hydrogen breath tests. Gut, 55(3), 297-303. doi:10.1136/gut.2005.075127
6) Yang, J.-F., Fox, M., Chu, H., Zheng, X., Long, Y.-Q., Pohl, D., … Dai, N. (2015). Four-sample lactose hydrogen breath test for diagnosis of lactose malabsorption in irritable bowel syndrome patients with diarrhea. World Journal of Gastroenterology, 21(24), 7563. doi:10.3748/wjg.v21.i24.7563
7) Methodology and Indications of H2-Breath Testing in Gastrointestinal Diseases: the Rome Consensus Conference. Alimentary Pharmacology & Therapeutics, 29: 1-49. 2009.
doi:10.1111/j.1365-2036.2009.03951.x
8) Atemtests bei gastrointestinalen Erkrankungen, ÖSTERREICHISCHE ÄRZTEZEITUNG, mai 2022, CAZ State of the Art
