Small intestinal bacterial overgrowth (SIBO) and intestinal methanogen overgrowth (IMO) commonly cause digestive symptoms like bloating, abdominal pain, and changes in bowel movements. SIBO and IMO are defined as an over-accumulation of bacteria and archaea, respectively, in the small intestine. Research has concluded that up to 36 million Americans suffer from SIBO. At-home breath testing can diagnose SIBO and IMO to support appropriate treatment recommendations for SIBO/IMO-related symptoms.
What is the SIBO/IMO Glucose Breath Test from Commonwealth Diagnostics International?
The SIBO/IMO glucose breath test utilizes a glucose substrate to measure gases produced by bacteria and archaea in the small intestine to diagnose SIBO and IMO. Bacteria and archaea ferment glucose as it travels through the small intestine before it is absorbed into the bloodstream. This fermentation produces hydrogen and methane gases, which are absorbed into circulation and exhaled through the lungs. After drinking the glucose solution, the patient performing the test will collect a series of breath samples at 15-minute timed intervals. The test takes 2 hours and 15 minutes to complete, and a total of 10 breath samples are collected during the test. Elevated gas levels measured in the breath reflect SIBO and/or IMO present in the first 2-3 feet of the small intestine.
Because glucose is absorbed by the small intestine, the glucose breath test cannot detect SIBO or IMO in the more distal portions of the small intestine. However, because of this, the glucose breath test is considered to produce fewer false positives than the lactulose breath test. The glucose breath test is also an alternative option for patients with a lactulose allergy who cannot perform the lactulose version of the test. (1)
What is the SIBO/IMO Lactulose Breath Test from Commonwealth Diagnostics International?
The SIBO/IMO lactulose breath test is identical to the glucose breath test, except that the patient drinks a lactulose solution at the beginning of the test. A lactulose breath test can diagnose SIBO and IMO in the small and large intestines because lactulose is not absorbed in the digestive tract (1). The lactulose breath test is also 2 hours and 15 minutes long, and the patient collects a total of 10 breath collections. The doctor ordering this test must have prescribing rights to prescribe the patient the lactulose included in the test kit.
Which Patients are the SIBO/IMO Breath Tests Best Used For?
SIBO/IMO breath bests can aid in diagnosing SIBO and IMO in patients experiencing typical digestive symptoms associated with SIBO and IMO. Bloating, abdominal pain, gas, constipation, diarrhea, and nutrient deficiencies are common signs and symptoms that SIBO and/or IMO are present. Research also suggests an increased risk and prevalence of SIBO in patients with irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and celiac disease. (2)
However, with increased awareness of SIBO and more research being performed, ample evidence suggests that SIBO is associated with symptoms and medical conditions outside of the digestive tract. Identifying and treating SIBO/IMO in patients with the following medical conditions may help to get to the root cause of the disease:
Emerging evidence supports that the gut microbiome helps to regulate metabolism, fat storage, and energy balance. Shifts in the normal intestinal microbiome composition have been connected to metabolic syndrome. Additionally, more recent evidence has shown that SIBO occurs more frequently in obese patients than non-obese patients. (2)
Gastroparesis, or slowed intestinal transit, is a consequence of diabetes caused by nerve damage. Slowed intestinal motility is a risk factor for SIBO, and studies have found an increased risk of SIBO among patients with type 2 diabetes. (2)
Intestinal dysmotility and dysbiosis are contributing factors to many rheumatologic and autoimmune diseases. SIBO has been documented to have higher prevalence rates in patients with systemic sclerosis, Behçet's disease, and bowel-associated dermatosis-arthritis syndrome. (2)
The "skin-gut axis" refers to the bidirectional relationship between the gut microbiome and skin health. Disruptions in the healthy microbiome and the development of SIBO have been linked to skin conditions, including rosacea, pyoderma faciale, and psoriasis. (2)
Impaired intestinal motility, slowed stomach emptying, and constipation are early signs of Parkinson's disease (PD). Gut motor dysfunctions are known to predispose an individual to SIBO, and IMO is highly correlated with chronic constipation. Studies have estimated up to 67% prevalence rate of SIBO in patients with diagnosed PD. (2)
Pro-inflammatory responses that contribute to liver disease have been measured in SIBO patients, and preliminary studies have concluded that treatment of SIBO in patients with non-alcoholic fatty liver disease (NAFLD) results in reduced markers of liver inflammation. (2)
How to Use the SIBO/IMO Breath Tests from Commonwealth Diagnostics International in Clinic
Patients must follow test preparation instructions before completing the glucose and lactulose SIBO/IMO breath tests. Patients should discontinue antibiotic, laxative, and promotility drugs and supplements up to four weeks before taking the test. Smoking and vaping 24 hours before and during the test can interfere with test accuracy. Additionally, patients should not sleep or exercise during the testing period.
Dietary restrictions are required 24 hours before test collection. The patient should eat only plain poultry, beef, pork, seafood, eggs, and white rice for 12 hours, followed by a 12-hour fasting period in which only water is permitted. The patient may return to their regular diet after completing the test.
The lactulose breath test is contraindicated for patients with a documented lactulose allergy. Caution should be taken ordering SIBO/IMO breath tests for patients with poorly-controlled diabetes, as blood sugar changes can occur with fasting and with drinking the glucose and lactulose solutions.
Per the North American Consensus, SIBO is diagnosed by a rise in hydrogen gas of at least 20 ppm by 90 minutes, and IMO is diagnosed by a methane level of at least 10 ppm at any time point during the test. It is possible to have co-existing SIBO and IMO. (1)
Research supports the treatment of SIBO and IMO with prescription antibiotics and/or antimicrobial herbal supplements. Probiotics have also been shown to reduce the bacterial burden and alleviate SIBO symptoms effectively. Dietary modifications are also commonly implemented during SIBO treatment protocols to palliate digestive symptoms frequently triggered by eating. (3)
The SIBO/IMO tests can be used to monitor treatment progress and confirm SIBO/IMO eradication after antibiotic therapy is completed. Waiting to retest four weeks after completing antibiotic treatment is generally not recommended for repeat tests, but all other preparatory instructions apply.
Small intestinal bacterial overgrowth and intestinal methanogen overgrowth are common conditions characterized by bacterial and archaeal overgrowth in the small intestine. Undiagnosed and untreated SIBO and IMO can cause disruptive digestive symptoms and contribute to symptoms unrelated to the digestive tract. Convenient at-home breath tests that diagnose SIBO and IMO help with treatment plan decision-making and monitoring.
Lab Tests in This Article
1. Rezaie, A., Buresi, M., Lembo, A., et al. (2017). Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus. The American Journal of Gastroenterology, 112(5), 775–784. https://doi.org/10.1038/ajg.2017.46
2. Losurdo, G., D’Abramo, F., Indellicati, G., et al. (2020). The Influence of Small Intestinal Bacterial Overgrowth in Digestive and Extra-Intestinal Disorders. International Journal of Molecular Sciences, 21(10), 3531. https://doi.org/10.3390/ijms21103531
3. Achufusi, T.G., Kachroo, P., Zamora, E., et al. (2020). Small Intestinal Bacterial Overgrowth: Comprehensive Review of Diagnosis, Prevention, and Treatment Methods. Cureus. https://doi.org/10.7759/cureus.8860