H. Pylori

The bacteria that normally live in your colon change undigested food that you eat or drink into gases and stool. Hydrogen and methane are two of those gases. These gases are cleaned out of the blood by your lungs when you exhale, and are collected and measured during the test.

The carbohydrate breath test indicates how completely your body digests certain foods by measuring how much hydrogen and methane your body makes after you eat these foods.