Does carbon 14 test require fasting?

Carbon-14 testing is usually performed on an empty stomach.

During carbon-14 testing, subjects take orally a drug containing carbon-14 markers. The drug reacts with Helicobacter pylori in the stomach to produce carbon-14-labeled carbon dioxide. Helicobacter pylori infection is then determined by measuring carbon-14-labeled carbon dioxide in the subject's exhaled breath. If food is eaten before the test, it affects the pH and pH of the stomach after entering the stomach. In particular, intake of foods high in protein and fat increases acidity in the stomach. Reaction of Helicobacter pylori with gastric acid is one of the conditions for its survival, and the presence of food may alter the acid-base balance in the stomach, thus affecting the reaction of Helicobacter pylori with carbon-14 labeled drugs. In addition, during carbon-14 testing, subjects need to take orally drugs containing carbon-14 labels. Ingredients in food may react with drugs, affecting the absorption and utilization of drugs, thus making drugs unable to fully react with Helicobacter pylori in the stomach, thus affecting the accuracy of test results.