What Is a Lactose Intolerance Breath Test?

Lactose intolerance, while not a serious condition, can be quite uncomfortable and can affect the quality of life. Symptoms such as bloating and diarrhea send patients to their gastroenterologist for a checkup. If your physician suspects lactose intolerance, they will order one of two different types of tests to determine if you’re lactose intolerant or not. Both are noninvasive and diagnostic. A lactose intolerance breath test will measure the amount of hydrogen in your breath, which can definitely let your doctor know that you have the condition.

What Is Lactose Intolerance?

Milk and dairy products contain a sugar called lactose. Those with lactose intolerance have difficulty fully digesting lactose, which can cause several different types of gastrointestinal disturbances. Everyone has a certain amount of lactase (an enzyme) that is produced in the small intestine. The lower the level of lactose in someone’s body, the more lactose intolerant they are. Also known as lactose malabsorption, lactose intolerance typically isn’t a serious condition, but its symptoms can be quite uncomfortable. Those with severe lactose intolerance may have to avoid dairy products to avoid symptoms, but many patients with lactose intolerance are able to consume small amounts of dairy with no symptoms.

What Are the Symptoms of Lactose Intolerance?

If you suspect you may be intolerant to dairy, you’ll experience noticeable symptoms within 30 minutes to 2 hours after consuming dairy products. The most common symptoms of lactose intolerance include:

• Bloating
• Gas
• Nausea and occasional vomiting
• Stomach cramps
• Diarrhea

Symptoms can be painful and uncomfortable. If you experience any type of gastrointestinal symptom that lasts for more than several days, you should consult your gastroenterologist. Many GI disorders share the same symptoms, and it’s important to get an official diagnosis and rule out more serious issues. 

What Are the Risk Factors for Lactose Intolerance?

With rare exceptions, everyone has enough lactase at birth to process lactose. For those who aren’t intolerant to lactose, the lactase in their bodies breaks down the sugar in milk (lactose) into galactose and glucose. Then, these are absorbed into the bloodstream through the intestinal lining. In patients with lactose intolerance, undigested lactose moves downward into the colon (large intestine) instead of being absorbed. This lack of absorption is what causes the symptoms associated with lactose intolerance. 

There are some risk factors associated with lactose intolerance, with the most prominent being increasing age. It’s more rare for children and younger adults to develop lactose intolerance because nearly everyone has enough lactase at birth. Lactose intolerance can appear suddenly. Some other risk factors include:

• Premature birth. Premature babies are born with less lactase, which can cause the onset of lactose intolerance later in life. 
• Ethnicity. Lactose intolerance is seen most often in those of Hispanic, African, Asian, and American Indian descent. 
• Cancer treatments. Radiation and chemotherapy increase the risk of developing lactose intolerance.
• Diseases of the small intestine. If you have a small intestine disorder, such as Crohn’s disease, celiac disease, or you have bacterial overgrowth in the small intestine, this places you at a higher risk for lactose intolerance. 

How Is Lactose Intolerance Diagnosed?

There are two types of tests to determine if you have lactose intolerance. One is the hydrogen breath test, which measures the amount of hydrogen in your breath, and the other is the lactose tolerance test, which measures the amount of glucose in your bloodstream several hours after drinking a beverage with an elevated lactose count. The more common of the two is the hydrogen breath test. There is a third test, a stool acidity test, but this is only used for infants and young children.

What Is the Hydrogen Breath Test?

The lactose intolerance breath test is a simple and noninvasive test. You will drink a beverage that has a high lactose count, and then expel your breath into a bag. The bag is then sent to the laboratory for testing. The test measures the amount of hydrogen in your breath. This is because when lactose goes undigested and moves to the colon instead of being absorbed, it creates an excess amount of hydrogen because the colon breaks the lactose down by bacteria. If you have higher than normal levels of hydrogen after drinking the beverage, then you are most likely lactose intolerant. 

How Do I Prepare for the Lactose Intolerance Breath Test?

There is not much preparation for the test. You will be asked to fast the night before, with nothing to eat or drink but water after midnight. Make sure you let your doctor know about any medications or over-the-counter supplements you are taking. You must stop taking any antibiotics or medication that affects the stomach two hours prior to the test. You may have to brush your teeth and rinse immediately before the test. 

What Is the Treatment for Lactose Intolerance?

The first-line treatment for lactose intolerance is to eliminate or avoid dairy based on the severity of the symptoms. Your gastroenterologist can help walk you through what amounts you can consume safely without becoming symptomatic. You can also add a liquid or powder lactase enzyme to milk to help break down the lactose. Maintaining good nutrition and having plenty of vitamin D in your diet is also a common recommendation. Your physician may also recommend a probiotic supplement, which is often used to treat other GI disorders, such as irritable bowel syndrome (IBS). They may also help your body digest lactose. Probiotics are generally safe, but consult your healthcare provider before beginning any new regimen.