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SIBO Breath Test Guide

Microbiota
December 24, 2024•3 min read

SIBO Breath Test Guide: What to Know Before Testing

If your doctor has recommended a SIBO breath test, you might wonder what to expect. This test, widely used for diagnosing Small Intestinal Bacterial Overgrowth, measures the gases (hydrogen, methane, and in some cases, hydrogen sulfide) released by bacteria in your small intestine. Here's a comprehensive guide on how the test works, how to prepare, and what your results mean.

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🤔How the SIBO Breath Test Works🤔

As the test begins, you’ll consume a sugar solution—typically glucose or lactulose—that bacteria ferment, producing measurable gases. My personal preference is for lactulose as the substrate because it is not absorbed by the GI tract, unlike glucose which is absorbed through the GI tract.

Over 2-3 hours, you'll provide breath samples at regular intervals 😮‍💨, which are analyzed for elevated gas levels. My preference here is for a 3-hour test because IMO (Intestinal Methanogen Overgrowth) can exist either in the small intestines or in the large intestines. Most people have a 2-hour transit time through the small intestines, which means that we need that third hour in order to gather information about overgrowth of methanogens that may exist in the large intestines.

Each gas measured provides insights:

  • Hydrogen: Linked to diarrhea-predominant SIBO. 💩💦

  • Methane: Indicative of Intestinal Methanogen Overgrowth (IMO), often associated with constipation.🚽🪨

  • Hydrogen Sulfide: As of 2024, Gemelli is the only lab that tests directly for this type of gas with their Trio-Smart kit. Elevated levels may explain both GI symptoms and symptoms of "toxicity" in cases where hydrogen and methane appear to be normal or even low.😵

✅Preparing for the Test✅

Accurate results depend on meticulous preparation. Here’s what you need to know:

Days Leading Up to the Test

  • Dietary Restrictions: Avoid fermentable foods like vegetables, fruits, grains, nuts, and dairy 24 hours before testing. A prep diet of plain proteins (e.g., chicken, fish, eggs), white rice, and clear broth is typically recommended the day before the test.

  • Medications: Discontinue antibiotics, laxatives, and probiotics at least 2 weeks before testing unless directed otherwise by your doctor.

The Night Before

  • Fasting: Stop eating and drinking (except plain water) at least 12 hours before the test.

Day of the Test

  • You may brush your teeth but avoid swallowing toothpaste or using mouthwash.

  • Do not smoke, exercise, or sleep during the testing hours, as these activities may interfere with results.

🔍Interpreting the Results🔍

Your healthcare provider will analyze the test results alongside your symptoms. Key findings might include:

  • Elevated Hydrogen Levels: Indicates hydrogen-dominant SIBO, often linked to bloating and diarrhea.

  • Methane Presence: Suggests methane-dominant SIBO (IMO), often tied to constipation.

  • Dual Gases: Both elevated hydrogen and methane may point to mixed SIBO, often requiring combined treatment approaches.

Common Pitfalls and Tips

  1. Incomplete Preparation: Not following pre-test instructions can lead to false results. Stick closely to dietary and medication guidelines, especially the day before testing. We have seen these false results in patients who didn't follow the guidelines, and that's a couple hundred dollars down the drain...and the need for another test. 😱

  2. False Positives/Negatives: Other conditions like rapid intestinal transit or carbohydrate malabsorption can mimic SIBO results. A flatline test (no gases detected) may indicate test errors or non-SIBO causes.

  3. Retesting: If symptoms persist after treatment, retesting may be necessary to confirm whether SIBO has been resolved.

💡Key Takeaways💡

  • The SIBO breath test is a non-invasive, effective diagnostic tool, but its accuracy relies on strict adherence to preparation guidelines. The kits come with very specific dietary guidelines to follow the day before testing. Watch and follow those guidelines closely! 👀

  • Understanding gas patterns helps tailor treatments, whether it's antibiotics, herbal antimicrobials, or dietary changes.

  • Work closely with your healthcare provider to interpret results and develop a treatment plan.

Next week, we’ll dive into the link between SIBO and mental clarity, exploring how SIBO affects brain fog and memory. Stay tuned! 🥰

Michael Arthur MD

Michael Arthur MD is a fully-certified functional medicine doctor, hypnotist, and RTT practitioner. He's on a mission to help and guide people with SIBO back to better health and digestive wellness.

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