Hydrogen breath test

Hydrogen breath test
Purposediagnostic tool for carbohydrate malabsorption and small intestine bacterial overgrowth

A hydrogen breath test (or HBT) is used as a diagnostic tool for small intestine bacterial overgrowth and carbohydrate malabsorption, such as lactose, fructose, and sorbitol malabsorption.[1][2]

The test is simple, non-invasive, and is performed after a short period of fasting (typically 8–12 hours).[3] Hydrogen breath tests are based on the fact that there is no source for hydrogen gas in humans other than bacterial metabolism of carbohydrates.[4] Even though the test is normally known as a "hydrogen" breath test, some physicians may also test for methane in addition to hydrogen. Many studies have shown that some patients (approximately 35% or more) do not produce hydrogen but actually produce methane. Some patients produce a combination of the two gases.[5] Other patients, who are known as "non-responders", don't produce any gas; it has not yet been determined whether they may actually produce another gas. In addition to hydrogen and methane, some facilities also utilize carbon dioxide (CO2) in the patient's breath to determine if the breath samples that are being analyzed are contaminated (either with room air or bronchial dead space air).

Physicians have expressed concern at the improper use and widespread overdiagnoses related to interpretation of these tests.[4][6]

  1. ^ Cite error: The named reference eisenmann was invoked but never defined (see the help page).
  2. ^ Rezaie, A (2017). "Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus". The American Journal of Gastroenterology. 112 (5): 775–784. doi:10.1038/ajg.2017.46. PMC 5418558. PMID 28323273.
  3. ^ Rana, Satya Vati; Malik, Aastha (2014-10-01). "Hydrogen Breath Tests in Gastrointestinal Diseases". Indian Journal of Clinical Biochemistry. 29 (4): 398–405. doi:10.1007/s12291-014-0426-4. ISSN 0970-1915. PMC 4175689. PMID 25298621.
  4. ^ a b Cite error: The named reference simren was invoked but never defined (see the help page).
  5. ^ de Lacy Costello BP, Ledochowski M, Ratcliffe NM (2013). "The importance of methane breath testing: a review". Journal of Breath Research (Review). 7 (2): 024001. Bibcode:2013JBR.....7b4001D. doi:10.1088/1752-7155/7/2/024001. PMID 23470880. S2CID 7675133.
  6. ^ Massey, Benson T.; Wald, Arnold (10 October 2020). "Small Intestinal Bacterial Overgrowth Syndrome: A Guide for the Appropriate Use of Breath Testing". Digestive Diseases and Sciences. 66 (2): 338–347. doi:10.1007/s10620-020-06623-6. ISSN 1573-2568. PMID 33037967. S2CID 222234070. Retrieved 24 October 2020.