Hydrogen-methane breath testing is valuable in clinical care for diagnosing small intestinal bacterial overgrowth (SIBO) and guiding treatment decisions. A recent paper by Tansel and Levinthal in Clinical and Translational Gastroenterology provides insights into the practical application of breath testing in real-world clinical scenarios, offering valuable information for gastroenterologists, dietitians, nutritionists, and other allied health providers.
Prevalence of SIBO and its Influence on Testing Utility
- Prevalence rates of SIBO vary across different patient populations encountered in routine practice.
- Understanding the prevalence helps determine the pretest probability and informs clinical decision-making.
- Consideration of testing thresholds and evolving protocols is crucial when interpreting prevalence estimates.
- Table 4 summarizes the prevalence of SIBO in various patient populations commonly encountered in gastroenterology practice.
CDI’s breath tests are rooted in extensive research, clinical studies, and scientific validation. Specializing in breath tests in our CLIA-certified laboratories since 2011, our diagnostic approach aligns with established clinical best practices and industry consensus guidelines, providing you with credible results that meet the highest standards of the medical community, including North American Consensus on Hydrogen and Methane Breath Testing and the ACG Clinical Guidelines for Small Intestinal Bacterial Overgrowth
Clinical Significance of GI Symptoms in SIBO Diagnosis
- Different GI symptoms exhibit varying relationships with SIBO.
- Diarrhea is strongly associated with SIBO, while other symptoms may have weaker relationships.
- Patients with positive breath test results and diarrhea and/or bloating symptoms tend to have better response rates to antibiotic treatment.
- Table 5 summarizes the performance characteristics of breath testing relative to specific GI symptoms.
Ratios in Interpreting Breath Test Results
- Likelihood ratios (PLR and NLR) play a crucial role in assessing the posttest probability of SIBO.
- A PLR of 2 or greater increases the likelihood of SIBO, while an NLR of 0.5 or lower decreases the likelihood.
- The Fagan nomogram provides a practical method for determining posttest probability based on pretest probability and likelihood ratios.
- Examples are provided to illustrate the application of likelihood ratios in clinical decision-making.
Breath Testing and Intestinal Methanogen Overgrowth (IMO)
- Methane breath testing helps identify patients with intestinal methanogen overgrowth (IMO).
- Breath testing for IMO should be reserved for patients with constipation as the dominant phenotype.
- Table 7 summarizes the prevalence of IMO in normal individuals and patients with IBS or inflammatory bowel disease.
CDI offers a wide range of testing options designed to address patients’ unique needs with functional GI disorders. Our breath tests for SIBO and IMO, available with glucose or lactulose substrate, provide flexible diagnostic approaches. Additionally, we offer fructose, sucrose, and lactose carbohydrate malabsorption breath tests, allowing you to tailor the diagnostic approach based on individual patient requirements. This comprehensive selection enhances diagnostic accuracy, leading to improved patient outcomes.
Billing and Cost Information
- Procedure codes (Current Procedural Terminology) for hydrogen-methane breath testing are provided.
- Relevant International Classification of Diseases, Tenth Revision codes associated with breath testing are listed.
- Typical out-of-pocket cost for patients without insurance is approximately $250 or less in the United States.
- At-home testing options are available, but patient compliance with preparation instructions is crucial for test accuracy.
CDI offers the lowest out-of-pocket maximum in the industry at $249 per breath test, ensuring that our tests are accessible and affordable for patients. CDI breath tests are also fully covered by Medicare, with no balance billing, so Medicare patients can undergo testing without financial concerns or unexpected bills.
The paper emphasizes the importance of understanding the performance characteristics and practical application of hydrogen-methane breath testing in diagnosing SIBO. By considering the prevalence of SIBO in specific patient populations, evaluating symptoms, and applying likelihood ratios, healthcare providers can make informed clinical decisions and improve patient outcomes. With the availability of at-home testing options, ensuring patient compliance with preparation instructions is essential to enhance test accuracy.
Clinical Use Case Example:
A patient with a diagnosis of celiac disease had relief of GI symptoms for a few years after initiating a gluten-free diet but recently has been experiencing symptoms of bloating and diarrhea in the past 4 months. The patient is confident in adherence to gluten avoidance, which is confirmed by negative celiac serology tests. Based on available data, the pretest probability of SIBO in this patient with celiac disease and active symptoms compatible with SIBO is 28% (Table 7). Breath testing has a positive predictive value of 2.45 and a negative predictive value of 0.60. Thus, using the Fagan nomogram, the posttest probability of SIBO with a positive glucose breath test is increased to 48.8%, and the posttest probability of SIBO with a negative glucose breath test is decreased to 18.9% (Figure 4). The breath test is ordered and comes back positive. The patient is offered treatment with a course of metronidazole, and the symptoms of diarrhea and bloating improve substantially.
Tansel, Aylin MD, MPH1; Levinthal, David J. MD, PhD1. Understanding Our Tests: Hydrogen-Methane Breath Testing to Diagnose Small Intestinal Bacterial Overgrowth. Clinical and Translational Gastroenterology 14(4):p e00567, April 2023. | DOI: 10.14309/ctg.0000000000000567