What is SIBO Breath Testing?
SIBO breath testing is a noninvasive diagnostic test used to detect small intestinal bacterial overgrowth, a condition where excessive bacteria in the small intestine interfere with nutrient absorption and digestion. SIBO can cause symptoms such as bloating, abdominal pain, gas, diarrhea, constipation, and malnutrition. The test measures hydrogen and methane gases produced when bacteria ferment carbohydrates.
When is Testing Recommended?
Testing is recommended for patients with persistent gastrointestinal symptoms or risk factors. Common indications include:
- Chronic bloating, gas, abdominal discomfort
- Unexplained diarrhea or constipation
- Irritable bowel syndrome symptoms
- Unexplained weight loss or nutrient deficiencies
- History of abdominal surgery or bowel disease
- Food intolerance, especially to sugars or fiber
- Conditions associated with motility disorders (e.g., diabetes, scleroderma)
Testing may also be used to monitor response to treatment or evaluate recurrence.
How is Testing Performed?
SIBO breath testing typically uses lactulose or glucose substrates. After fasting, the patient drinks a small amount of test sugar, and breath samples are collected every 15 to 20 minutes over several hours. The samples are analyzed for hydrogen and methane levels, which indicate bacterial fermentation in the small intestine. Results help determine whether SIBO is present and identify hydrogen-predominant, methane-predominant, or mixed gas patterns.
What to Expect After Testing?
SIBO breath testing is noninvasive, and patients can resume normal activities immediately. Some individuals may experience temporary bloating or gas due to test sugars, but symptoms typically resolve quickly.
What are the Risks of Testing?
The test is considered safe. Possible minor effects include:
- Temporary bloating or abdominal discomfort
- Nausea in sensitive individuals
- False positives or negatives if dietary prep is not followed
What are the Benefits of Testing?
Key benefits include:
- Identifying the presence and type of bacterial overgrowth
- Guiding targeted antibiotic or dietary therapy
- Differentiating SIBO from IBS and other GI disorders
- Helping prevent chronic symptoms and nutritional deficiencies