Evaluation of Fructose Breath Test Results

When fructose is not fully absorbed, it passes from the small intestine to the large intestine or colon. Our colon has bacteria that will degrade fructose to simple gases like hydrogen or methane. It is thought that these gases are responsible for the gastric distress that some people feel after consuming foods containing fructose. In the fructose hydrogen breath test, we administer a 25 gram amount of fructose and collect breath samples for 3 hours.

Each breath sample is analyzed for hydrogen, methane and carbon dioxide levels. The hydrogen and methane levels are standardized to the amount of breath carbon dioxide in the sample we receive. We determine the change in hydrogen and methane from the initial breath collection. A change of at least 20 parts per million is considered fructose malabsorption. Shown below are examples of normal and fructose malabsorption test results.

Normal

Fructose Malabsorption