Lactose Intolerance Breath Test


Lactose intolerance is the most common food intolerance in the world. People who have trouble digesting lactose can learn, by testing themselves, which dairy products and other foods they can eat without discomfort and which ones they should avoid. Many will be able to enjoy milk, ice cream, and other such products if they take them in small amounts or eat other kinds of food at the same time. Others can use lactase liquid or tablets (Lactaid®) to help digest the lactose. Even older women and children who must avoid milk and foods made with milk can meet most of their special dietary needs by eating greens, fish, and other calcium-rich foods that are free of lactose. A carefully chosen diet (with calcium supplements if the doctor recommends them) is the key to reducing symptoms and protecting future health.

Lactose intolerance is the inability to digest significant amounts of lactose, which is the predominant sugar of milk. Close to 50 million American adults is lactose intolerant. Certain ethnic and racial populations are more widely affected than others. As many as 75 percent of all African-American, Jewish, Native American, and Mexican-American adults, and 90 percent of Asian-American adults are lactose intolerant. The condition is least common among people of northern European descent.


What Causes Lactose Intolerance?

Lactose intolerance results from a shortage of the enzyme lactase, which is normally produced by the cells that line the small intestine. Lactase breaks down milk sugar into simpler forms that can then be absorbed into the blood stream. When there is not enough lactase to digest the amount of lactose consumed, the results, although not usually dangerous, may be very distressing.

Common symptoms include nausea, cramps, bloating, gas, and diarrhea, which begin about 30 minutes to two hours after eating or drinking foods containing lactose. Many people who have never been diagnosed as lactose intolerant or “lactase deficient” may notice that milk and other dairy products cause problems that don’t occur when eating other foods. The severity of symptoms varies depending on the amount of lactose each individual can tolerate.

Some causes of lactose intolerance are well known. For instance, certain digestive diseases and injuries to the small intestine can reduce the amount of enzymes produced. In rare cases, children are born without the ability to produce lactase. For most people, though, lactase deficiency is a condition that develops naturally, over time. After about the age of two years, the body begins to produce less lactase. However, symptoms may occur years after childhood.


What is the Hydrogen Breath Test for Lactose Intolerance?

The hydrogen breath test measures the amount of hydrogen in the breath. Normally, no hydrogen is detectable in the breath. However, undigested lactose leads to the formation of various gases including hydrogen, by bacteria in the colon. The hydrogen is absorbed from the intestines, carried through the bloodstream to the lungs, and exhaled. In the test, the patient drinks a lactose-loaded beverage, and the breath is analyzed at regular intervals. Hydrogen in the breath means improper digestion of lactose. Certain foods, medications, and smoking can affect the test’s accuracy and may need to be avoided before the test.


Instructions for the Hydrogen Breath Test for Lactose Intolerance

A baseline hydrogen level in your breath will be obtained at the time of your first visit. This requires only that you breathe into our machine. Formal testing will be performed at your next visit.

  • On the day before testing, do not eat beans, bran, or high fiber cereals.
  • Fast for 12 hours, with no food and only water to drink before testing.
  • Do not smoke, sleep or exercise vigorously for at least ½ hour before, or at any time during testing.
  • Please alert us about any recent antibiotic use and/or recent or current diarrhea as this may affect the result of the test.
  • Three hours before your appointment, drink 12 oz of milk. It does not matter if you drink skim, 1%, 2% or whole milk, but you CANNOT drink Lactaid milk.

The result of the test will be given to you by the nurse or the physician before you leave the office.

Eric Morgenstern, MD PLLC