Hydrogen-methane breath test with lactulose

In a healthy person, hydrogen and / or methane are absent in the exhaled air on an empty stomach, since they are not produced during metabolism.

The release of these gases with respiration occurs when carbohydrates are broken down by anaerobic intestinal bacteria, the vast majority of which are in the colon. In the small intestine, they are present only in small quantities.

With excessive bacterial growth, the number of anaerobic bacteria in the small intestine can increase significantly, which leads to increased production of hydrogen or methane. This condition is called bacterial overgrowth syndrome (SIBR).

Hydrogen-methane breath test with lactulose is a modern method that is used to diagnose disorders of the microflora of the small and large intestine and intolerance to carbohydrates (lactose, sucrose, fructose).

When is a breath test scheduled?

The study is performed in patients with:

  • irritable bowel syndrome;
  • syndrome of excessive bacterial growth in the small intestine;
  • diverticulosis of the small intestine;  
  • bloating, excessive gas formation;
  • diarrhea.

And also, for:

  • determination of the time of the oral passage;
  • identification of conditions in which hydrogen is not produced.

The test results make it possible to make an objective clinical picture, make an accurate diagnosis and subsequently prescribe adequate treatment.

Who can not conduct a hydrogen test?

Absolute contraindications to the test are:

  • The existing hypoglycemia of fasting or suspicion of it.
  • Allergy to lactulose (the drug that the patient takes during the study).  
  • The presence of an ileostomy (an artificial opening on the abdominal cavity to remove feces).

How is the procedure performed?

1. For the study, exhaled air samples are used to measure the basal level of gases in the exhaled air against the background of starvation, before taking the test substance.

2. The first basic test is carried out either using a special package, or directly exhaling is performed into the device using a disposable mouthpiece.

3. Immediately after receiving the results of the baseline test, it is necessary to drink the entire prepared solution with the lactulose preparation.

4. Subsequent samples are carried out through 15, 30, 45, 60, 75, 90, 120 minutes.

5. The total time of the test is 2 hours.

Symptoms that often appear during a breath test:

  • Rumbling in the stomach
  • Bloating
  • Diarrhea
  • Abdominal pain
  • Nausea
  • Heartburn
  • Belching
  • Fatigue
  • Dizziness
  • Headache
  • Feeling cold or hot

How to prepare for the test?

  • The SIBR test should be performed in the morning.
  • Strictly on an empty stomach, after a night fasting period of 12 to 14 hours.
  • In the morning before the test, it is recommended to brush your teeth and drink a glass of hot water.
  • The last meal (in the evening) before the test should be light and not contain dietary fiber (exclude dietary supplements and foods rich in fiber).
  • Eliminate physical and emotional overload on the eve of the study and during the test.
  • 1 week before the test, exclude the use of laxatives and prokinetics (motility regulators).
  • 24 hours before the test, exclude dairy products, juices, onions, garlic, cabbage, legumes, pickled vegetables, complex carbohydrates and vitamins from the diet.
  • 12 hours before the test, eliminate smoking and chewing gum.

Before the test, it is forbidden to use adhesive substances for prostheses on the day of the test (patients wearing prostheses). Also, it is impossible to conduct a study earlier than four weeks after the end of antibiotics, colonoscopy or X-ray examination of the small intestine by Sellink.

What is the result of the study?

The patient is issued a conclusion. In case of a positive result, he is recommended to consult a gastroenterologist for the selection of drug therapy.


In the laboratory of functional diagnostics of intestinal diseases MCSC named after A.S. Loginov, you can undergo this study on high-precision equipment.

Sign up for a hydrogen-methane breath test with lactulose by phone 8-800-234-24-22

Стоимость

3-15 Водородно-метановый дыхательный тест с лактулозой, диагностика синдрома избыточного бактериального роста (СИБР) - 3600 rubles

GBUZ Moscow Clinical Scientific Center named after Loginov MHD