Breath Test

The Breath Test is a non-invasive diagnostic test that evaluates the digestion and absorption of certain carbohydrates, as well as detects alterations in intestinal fermentation.

By analyzing exhaled air, the production of hydrogen (H₂), methane (CH₄) and, in some profiles, hydrogen sulfide (H₂S), gases generated by the intestinal microbiota during the fermentation processes after ingesting a specific substrate (lactose, fructose, sorbitol, lactulose, or glucose).

The quantification of these gases, along with the temporal evolution of the values and the appearance of symptoms during the test, provides relevant information for the evaluation of carbohydrate intolerances and small intestinal bacterial overgrowth (SIBO).

WHEN IS IT INDICATED?

The Breath Test is indicated as a diagnostic tool in the following contexts:

• Suspicion of intolerances, due to enzymatic deficiency or malabsorption, depending on the substrate administered.
• Evaluation of small intestinal bacterial overgrowth (SIBO), through the use of lactulose or glucose.
• Study of persistent digestive symptoms such as: abdominal distension, gas, abdominal pain, diarrhea, or alterations in intestinal rhythm.

WHAT DOES THE TEST ANALYZE?

The study includes the determination of gases after the administration of the following substrates:

• Lactose
• Fructose
• Sorbitol
• Lactulose (SIBO Test)
• Glucose

Each substrate allows for the evaluation of different mechanisms of digestion, absorption, or intestinal fermentation, so the choice must be adjusted to the clinical context and diagnostic suspicion.

The interpretation of the Breath Test is not based solely on an isolated value, but on the temporal curve of gas production, the type of gas predominating, and the correlation with the symptomatology during the test. For this reason, it is a test that should always be integrated into a global clinical assessment, as a support to the diagnosis.