From the Guidelines
Yes, there are tests available to diagnose lactose intolerance, with the hydrogen breath test being a common method. The diagnosis of lactose intolerance can be approached through various methods, including:
- Hydrogen breath test: This test measures the amount of hydrogen in the breath after consuming lactose, which is produced by bacteria in the colon when lactose is not properly digested by the body 1.
- Lactose tolerance test: This test measures blood sugar levels after consuming lactose to assess the body's ability to digest it.
- Stool acidity test: This test is sometimes used in infants and children to diagnose lactose intolerance.
- Intestinal biopsy: Although rarely necessary, this test can check for lactase enzyme activity in the small intestine.
- Elimination diet: Removing lactose-containing foods from the diet for a period and then reintroducing them to observe symptoms can also help diagnose lactose intolerance. It's essential to note that lactase deficiency, which leads to lactose malabsorption, is common in most non-Caucasian population groups after the age of two years, as lactase activity decreases rapidly in these individuals 1. In clinical practice, the choice of test depends on the patient's symptoms, medical history, and the availability of testing methods. Considering the potential impact of lactose intolerance on quality of life, morbidity, and mortality, accurate diagnosis and appropriate management are crucial to alleviate symptoms and prevent complications.
From the Research
Diagnostic Methods for Lactose Intolerance
- The diagnosis of lactose intolerance can be made using various methods, including genetic tests, hydrogen breath tests (HBT), quick lactase tests, and lactose tolerance tests 2.
- The hydrogen breath test is the most commonly used method due to its non-invasive nature, low cost, and high sensitivity and specificity 2.
- Other tests, such as blood tests, genetic mutation analyses, and urine tests, are also available for diagnosing lactose intolerance 3.
- The lactose tolerance test is another method used to diagnose lactose intolerance, which measures the body's ability to absorb lactose 4.
Comparison of Diagnostic Tests
- A study compared the lactose hydrogen breath test and lactose tolerance test in diagnosing lactose malabsorption, and found that 65% of patients were positive for lactose HBT, while 71% were positive for LTT 4.
- Another study found that a lower lactose load (12.5g) may be more appropriate for diagnosing lactose intolerance, as most patients with a positive HBT-25 test normally absorb a lower dose of lactose 5.
- The presence of symptoms during the lactose tolerance test was not useful for predicting a positive low-dose test, while the absence of symptoms had a high negative predictive value for a negative low-dose test 5.
Clinical Implications
- Accurate diagnosis of lactose intolerance is essential to prevent self-diagnosis and unnecessary elimination of milk and dairy products from the diet, which can lead to nutrient deficiencies 3.
- A diagnosis of lactose intolerance can be made using a combination of clinical evaluation, medical history, and diagnostic tests, such as HBT or LTT 6.
- Treatment of lactose intolerance can include a lactose-reduced diet, enzyme replacement, and other therapeutic options, such as probiotics and prebiotics 2, 6.