Understanding Your SIBO Breath Test Results
For many people with bloating, constipation, diarrhea, abdominal pain, or other digestive issues, breath testing is one of the most valuable tools available to help you find out what’s happening inside your gut. But reading the results–and understanding how they relate to your symptoms and possible avenues for treatment–may feel overwhelming.
If you’ve taken the Trio-Smart 3-Gas Breath Test and you are looking for clarification about your results, or if you are interested in finding out more about what the test measures and if breath testing could benefit you in your journey to find answers, you’ve come to the right place. This article is designed to help both patients and providers decode Trio-Smart breath test results in a clear, accessible way. By the end you’ll know exactly how the test works, how each gas could be correlated to your symptoms and potential diagnosis, what the numbers indicate, and possible next steps for you to take to find relief.
But first, an important disclaimer: Internet research is not a substitute for medical care. This article is for educational purposes only and does not constitute medical advice. Please consult a licensed healthcare provider to interpret your results and guide your treatment.
Table of Contents
What is the Purpose of Breath Testing?
A healthy gut contains trillions of microorganisms that aid your body in breaking down the food you consume, digesting it, and absorbing the life-sustaining nutrients it contains. This collection of microorganisms includes key species of bacteria and archaea, and is collectively called your gut microbiota. When the types and numbers of these microorganisms are well-balanced, your gut can work in a normal, rhythmic fashion, digesting and moving food through your gastrointestinal tract without problems.
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But, when your microbiota becomes imbalanced–as is the case when some of these microorganisms start to become too abundant and create a microbial overgrowth–the normal function and motility (the movement of your food through your system) becomes disrupted, causing many kinds of debilitating symptoms that affect your health and quality of life.
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Through years of extensive research, scientists now know that these microbes in your gut produce certain gases as they ferment the sugars and fibers in your food. And importantly, these gases are not random. Specific gases are produced by specific types of microbes and are associated with particular patterns of symptoms. So, by measuring the presence and prevalence of these gases, you and your healthcare providers can determine if you have a microbial overgrowth, which type of overgrowth is most likely, and what kind of treatment plan is most appropriate for your specific condition.
What Does the Trio-Smart 3-Gas Breath Test Measure?
The Trio-Smart 3-Gas Breath Test is the only breath test currently available that measures all three key gases produced by your gut microbiota: hydrogen (H2), methane (CH4), and hydrogen sulfide (H2S).
Scientifically validated studies have demonstrated that these three gases can be positively correlated to the three most common microbial overgrowths and their associated conditions:
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Hydrogen is typically produced by bacteria in the small intestine. Normally, your small intestine contains very few bacteria compared to the large intestine (colon) but many conditions that affect your gut motility can lead to a surplus of bacteria multiplying in your small intestine. When this happens, the excessive numbers of bacteria produce elevated levels of hydrogen, which is often indicative of Small Intestinal Bacterial Overgrowth (SIBO). Symptoms of SIBO can include bloating, abdominal pain, gas, abdominal distension, indigestion, constipation, and diarrhea. Bloating is the most commonly reported symptom of SIBO.​​
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Methane is actually produced by microbes called archaea, which are microorganisms that are somewhat similar to bacteria, but with some biological differences. Archaea consume hydrogen and release methane as a byproduct. High levels of methane are associated with Intestinal Methanogenic Overgrowth (IMO). Patients with IMO often report similar symptoms to those with SIBO, but with a notably higher prevalence of moderate to severe constipation.
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Hydrogen sulfide is produced when specific sulfate-reducing bacteria in the gut consume hydrogen and sulfur-containing compounds. This gas has a distinctive “rotten egg” smell and, when elevated, is often associated with Intestinal Sulfide Overproduction (ISO). ISO also shares many common gastrointestinal symptoms like bloating, abdominal pain, gas, nausea, and diarrhea. However, emerging research indicates that the most telling symptom of ISO is diarrhea, with higher hydrogen sulfide concentrations correlating strongly with an increased prevalence and severity of diarrhea in many patients. For many years ISO and hydrogen sulfide-correlated diarrhea went underdiagnosed, as hydrogen sulfide was not detectable by standard breath tests. But, the Trio-Smart 3-Gas Breath Test measures the H2S levels in your breath, giving you a much more complete picture of the microbial overgrowth in your gut.
How the Test Works
The Trio-Smart breath test is performed after a preparatory period involving low-fermentation diet and fasting. The actual test involves drinking a sugar solution–either lactulose or glucose–and then collecting breath samples every fifteen minutes for a two hour period. The sugar from the ingested solution travels through your digestive system and into your intestines where it is fermented by microorganisms, thus producing gases as byproducts. Those gases are absorbed into your bloodstream and exhaled through the lungs as part of your breath.
Your collected breath samples are then sent back to the lab, where they are analyzed for hydrogen, methane, and hydrogen sulfide. Carbon dioxide (CO2) is also measured in each sample to provide confirmation that the sample was collected correctly from the lower lungs, ensuring accuracy. Each of the three gases has its own threshold for what is considered “normal” or “elevated” based on recommendations from the North American Consensus on Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders. These thresholds help providers determine whether you may be experiencing microbial overgrowth and what type of treatment might be most effective.
Understanding the Thresholds
After your breath test samples have been analyzed, you are provided with a report detailing your findings, with charts and graphs showing how much of each gas was present at each 15-minute interval during the testing period. You can see a sample Trio-Smart Breath Test report here. The results are measured in parts per million (ppm) allowing you to compare your gas levels to the standard thresholds:
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Hydrogen levels are considered elevated when there is a rise of 20 ppm or more from the baseline within the first 90 minutes of the test. The “baseline” is determined from your breath sample taken before the ingestion of the sugar solution. So, this threshold is comparing the levels of hydrogen in your breath after ingesting the solution to the one before ingesting it, and looking to see how much the hydrogen level rises. A rise in hydrogen beyond the threshold is supportive of a possible SIBO diagnosis.
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Methane levels are considered elevated when they are 10 ppm or higher at any point during the test. Even one reading of 10 ppm or higher can indicate above normal levels of methane. This is supportive of a possible IMO diagnosis.
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Hydrogen sulfide levels are considered elevated when they are 3 ppm or higher at any point during the test. Even one reading of 3 ppm or higher can indicate above normal levels of hydrogen sulfide. This is supportive of a possible ISO diagnosis.
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A note about “Borderline” Hydrogen Sulfide Levels: As data continues to accumulate around the increasing importance of hydrogen sulfide and its relationship to symptoms such as diarrhea and abdominal pain, medical understanding of this threshold is evolving. A 2022 study demonstrated that in diarrheal IBS patients, a hydrogen sulfide level greater than 2 ppm was notably distinguishable from patients with constipation IBS, and this level was also associated with great H2S-producing bacteria in the gut. For this reason your results may make note of any hydrogen sulfide level above 2 ppm, and it is recommended that you consult your healthcare provider(s) about this result so they can use good clinical judgment in determining whether your findings merit treatment specific to your condition(s) and symptoms.
It’s important to note that these gases and the microbes that produce them don’t operate in isolation. Hydrogen is the common fuel–produced by bacteria fermenting the sugars and fibers in your gut–and it can be consumed by other organisms to produce either methane or hydrogen sulfide. This means that sometimes the presence of one gas can suppress or mask the presence of another. For example, if hydrogen is being consumed rapidly by methanogens (like the archaea associated with IMO) hydrogen levels may appear low, even if there is an overgrowth problem. That’s one of the major reasons why it’s so important to test for all three gases and then discuss your findings with your healthcare provider(s) to ensure proper assessment of your specific results and conditions.
Trio-Smart in Action: Examples of Possible Cases
With a more complete picture of what’s going on inside your gut, you can identify treatment and management plans that are tailored to your specific needs and aimed at getting you the relief that you deserve. To help you get a fuller picture of how breath testing can fit into your quest for gut health answers, let’s take a look at some hypothetical examples of common presentations of symptoms and their corresponding results.
Example 1–Sofia often experiences bloating and a mix of constipation and diarrhea. Her Trio-Smart results show a rise in hydrogen gas of 25 ppm within 45 minutes of the start of her test, while methane and hydrogen sulfide remain within normal limits. This pattern suggests Sofia might have SIBO, so her doctor recommends a course of antibiotics, followed by a low-fermentation diet.
Example 2–Jamal has a long history of constipation and hard, pellet-like stools. His Trio-Smart test reveals a methane level of 15 ppm at baseline and remains elevated throughout, while his hydrogen and hydrogen sulfide levels remain stable and within normal limits. This pattern suggests Jamal may have IMO, and his doctor believes he may benefit from a dual-antibiotic therapy and a diet focused on maintaining healthy gut motility.
Example 3–Liam has chronic loose stools and complains of excessive gas and fatigue. His hydrogen sulfide levels are consistently above 4 ppm, while other gases are normal. This pattern suggests that Liam may have ISO, so his doctor recommends antibiotic treatment and long-term management of his symptoms with Pepto Bismol and a low-sulfur diet.
These examples are only meant to be illustrative and they are by no means exhaustive. Every person is unique and every case is different. So, it is vital that you compile as much information as possible and review your specific symptoms and conditions with your healthcare provider(s) to find the right diagnosis, treatment, and management plan for you.
Why Retesting Matters
As you progress through your gut health journey, you may find it beneficial to retest your gas levels in the future. Retesting can help you and your provider(s) assess whether gas levels have returned to normal and can help confirm whether your treatment and management plan is working. It’s also useful for tracking symptoms that may persist or recur, especially if your original results indicated elevations in more than one gas.
Ultimately, our goal at Gemelli Biotech is to support you in your quest for answers, and help you get on the road to a healthier, happier life. We hope you’ve found this article useful. For more information on SIBO, IMO, and ISO, please check out all the other resources at triosmartbreath.com.