Hydrogen Breath Test

Uses of Hydrogen Breath Testing

A hydrogen breath test (HBT) is crucial in diagnosing gastrointestinal disorders related to carbohydrate malabsorption, such as lactose intolerance and bacterial overgrowth in the small intestine. The test measures the amount of hydrogen gas and sometimes methane in the exhaled breath, which can indicate malabsorption or abnormal microbial metabolism in the gut.

Carbohydrates and certain sugars not absorbed in the small intestine can be fermented by bacteria in the colon, producing hydrogen and methane gases. These gases are absorbed into the blood and eventually exhaled in the breath. Therefore, abnormally high levels of these gases can signal malabsorption or bacterial overgrowth.

The results of an HBT can fluctuate based on several factors, including the individual's baseline levels of hydrogen and methane, the type of carbohydrate ingested during the test, and certain types of bacteria in the colon. Variations in test results can also occur due to differences in individual metabolism, dietary patterns, and gut flora composition. Understanding these fluctuations is essential to interpreting and diagnosing gastrointestinal diseases and disorders.

HBTs are non-invasive and safe, making them a preferred method for diagnosing carbohydrate malabsorption and small intestinal bacterial overgrowth (SIBO). They are precious for individuals who experience symptoms like bloating, gas, abdominal pain, diarrhea, and constipation, which are common in these conditions. Hydrogen breath tests help tailor dietary recommendations and treatments to improve gastrointestinal health and quality of life for patients experiencing these symptoms by identifying specific malabsorption issues.

Does this test have other names?

The HBT is known by various names, reflecting its applications and the specific carbohydrates used during the test. Some of the common synonyms include:

• Lactose hydrogen breath test
• Fructose hydrogen breath test
• Glucose hydrogen breath test
• Lactulose hydrogen breath test
• Methane breath test
• Breath hydrogen test (BHT)

Each of these tests has its unique purpose and methodology, tailored to diagnose different conditions related to carbohydrate digestion and gut-bacterial balance. The choice of the test depends on the patient's symptoms and the suspected underlying condition.

What are the different types of hydrogen breath tests?

HBTs vary depending on the specific carbohydrate used and the health condition they aim to diagnose. Here's a closer look at each type:

• Lactose hydrogen breath test: The lactose breath test is designed to diagnose lactose intolerance. Patients ingest a lactose-rich solution, and hydrogen levels in the breath are measured at regular intervals. If lactose malabsorption happens due to a lack of lactase enzyme, it ferments in the colon, producing hydrogen. Typically, 25 grams of lactose is used, and elevated hydrogen levels indicate that the patient is lactose intolerant.
• Fructose hydrogen breath test: The fructose breath test helps diagnose fructose malabsorption, which involves ingesting fructose and measuring hydrogen levels in the breath. Fructose malabsorption occurs when the body cannot properly break down fructose in the small intestinal tract, indicating intolerance and leading to fermentation and hydrogen production. A common dose for the test is 25 grams of fructose.
• Glucose hydrogen breath test: The glucose breath test identifies small intestinal bacterial overgrowth (SIBO). Patients consume a glucose solution, and hydrogen is produced if bacteria in the small intestine ferment the glucose. A standard dose is 75 grams of glucose. Elevated hydrogen levels soon after ingestion indicate bacterial overgrowth.
• Lactulose hydrogen breath test: Lactulose, a non-digestible sugar, is used in this test to detect SIBO. Since lactulose isn’t absorbed in the small intestine, it reaches the colon, where bacteria ferment it, producing hydrogen. The dose in a lactulose breath test is 10 grams, and an early rise in hydrogen levels suggests bacterial overgrowth in the small intestine.
• Methane breath test: This test measures methane levels and is often performed alongside hydrogen breath tests. Some individuals produce methane rather than hydrogen. Conditions like constipation-predominant IBS are associated with higher methane production. The dosage and carbohydrate used may vary depending on the concurrent hydrogen breath test.

How does the Hydrogen Breath Test work?

The HBT is a non-invasive method to diagnose various gastrointestinal disorders. Here's a step-by-step guide on how this test typically works:

Step 1: Pre-test preparation

Patients are usually asked to follow a specific diet 24-48 hours before the test. They cannot eat or drink certain foods that could affect the results, such as milk, dairy products, fruit juices, or even chewing gum. They cannot take antibiotics or fiber supplements, either. Usually, patients are recommended to eat white rice and broiled chicken without sauces or seasoning. Fasting for at least 12 hours before the test is also required to ensure that the stomach and intestines are clear.

Step 2: Baseline breath sample

Upon arriving for the test, a baseline breath sample is collected. This initial sample is crucial as it provides a comparison point for subsequent measurements.

Step 3: Ingesting the test solution

Patients consume a liquid solution containing a specific type of sugar, such as lactose, fructose, glucose, or lactulose. The choice of sugar depends on the suspected condition being tested.

Step 4: Regular breath sampling

After ingesting the sugar solution, breath samples are taken at regular intervals, typically every 15-30 minutes, for 2-3 hours. These samples are analyzed to measure the levels of hydrogen and, in some cases, methane.

Step 5: Analyzing the results

The collected breath samples are analyzed to determine the concentration of hydrogen and methane. An increase in these gases can indicate poor digestion or absorption of the ingested sugar or abnormal bacterial growth in the small intestine.

Step 6: Post-test consultation

After the test, patients typically consult with their healthcare provider to discuss the results. Further diagnostic procedures or treatment plans may be discussed if abnormalities are detected.

How should my client prepare for the hydrogen breath test?

Preparing correctly for a hydrogen breath test is crucial for accurate results. Here’s how clients should prepare:

• Dietary restrictions: In the 24-48 hours leading up to the HBT, following a specific diet to minimize factors that could interfere with the results is essential. Avoid high-fiber foods and carbohydrates that might ferment in the gut, such as pasta, bread, cereals, and certain fruits and vegetables. Patients should avoid dairy products, nuts, seeds, and high-sugar foods. Recommended foods include plain chicken, fish, white rice, and eggs. Beverages should be limited to water only; avoid alcohol, coffee, tea, and fruit juices.
• Fasting: Patients must fast for at least 12 hours before the test. This means no food or drink, except water, should be consumed during this period. Fasting ensures that the stomach and intestines are straightforward, providing a clean baseline for the test.
• Medication: Certain medications can impact the test results and should be discussed with a healthcare provider. Patients should inform their doctor about all their medications, including over-the-counter drugs and supplements. Particular attention should be paid to antibiotics, as they can significantly alter gut flora and potentially skew test outcomes.
• Smoking: Smoking, including exposure to secondhand smoke, should be avoided on the day of the test, as it can affect the results. Nicotine and other substances in the smoke can influence digestive function and may alter the levels of gases measured in the breath.
• Physical activity: Patients should avoid strenuous physical activity the day before and on the test day. Excessive physical exertion can affect metabolic rates and the balance of gases in the body.
• Other considerations: Patients should inform their healthcare provider if they have any underlying health conditions, especially those related to the digestive system. It’s also important to discuss any recent gastrointestinal surgeries or procedures, as these can impact test results.

Are there any risks or side effects to the hydrogen breath test?

The HBT is generally safe and non-invasive, but it may have some risks or side effects like any medical procedure. Here are the most common ones:

• Discomfort or bloating: One of the most common side effects of the hydrogen breath test is abdominal discomfort or bloating. This occurs because the test often involves ingesting substances (like lactose, fructose, or glucose) that can cause gas production, especially in individuals with sensitivities or intolerances to these sugars.
• Nausea: Some patients may experience nausea during the test, mainly if they are sensitive to the test sugars. Drinking the sugar solution on an empty stomach can exacerbate this feeling.
• Diarrhea: In rare cases, ingesting test sugars can lead to diarrhea, especially in individuals who are intolerant to these sugars. This is more common in tests for lactose intolerance or fructose malabsorption.
• False positive or negative results: There's a risk of false positive or negative results, particularly if the patient has not adhered to the preparation guidelines. Factors like recent antibiotic use, improper fasting, or smoking can affect the accuracy of the test.
• Allergic reactions: Though rare, allergic reactions to the sugar solutions used in the test can occur. Patients with known allergies should inform their healthcare provider beforehand.

As a healthcare provider, you must discuss these potential risks and side effects with your patient before the test. This ensures that patients are fully informed and can make the best decisions regarding their healthcare.

What might affect the test results?

Certain factors can influence the results of an HBT, potentially leading to inaccurate readings. Here are some key elements that healthcare providers and patients should be aware of:

Dietary factors: The patient's diet before the test can significantly affect the results. Consuming certain foods and beverages, particularly those high in carbohydrates or sugars, can lead to elevated baseline hydrogen levels, skewing the test outcome. Patients are usually advised to follow a specific diet 24-48 hours before the test, avoiding foods like bread, pasta, fiber-rich fruits and vegetables, dairy products, and sugary snacks.

Smoking: Smoking, including exposure to secondhand smoke, can alter the results of the hydrogen breath test. Smoking can affect the digestive system and the bacteria in the gut, potentially leading to changes in hydrogen production. Patients are typically advised to avoid smoking on the day of the test.

Medications: Certain medications, particularly antibiotics, can impact the test results. Antibiotics can alter the gut flora, affecting hydrogen production and producing false results. Patients are generally advised to avoid antibiotics for a period before the test, as recommended by their healthcare provider.

Bowel movements: Irregular bowel movements or conditions like constipation can influence the test results. They can affect the transit time of food and the test solution through the gut, potentially leading to inaccuracies in hydrogen measurement.

Baseline hydrogen levels: Individual variations in baseline hydrogen levels can also impact the test. Some people naturally have higher or lower levels of hydrogen in their breath, which can influence the interpretation of the test results.

Healthcare providers should ensure that patients know these factors. Proper preparation and understanding of these influences can help ensure the most accurate results from the hydrogen breath test.