SIBO 102: Diagnosis and Treatments

(Audio) SIBO 102: Diagnosis and Treatments

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If you've already heard of Small Intestinal Bacterial Overgrowth (SIBO) and suspect it might be behind your persistent bloating, gas, or digestive discomfort, you're not alone—and you're in the right place. In this post, we’ll explore how this often-overlooked condition is accurately diagnosed and what evidence-based treatment options are available. If not familiar with SIBO, I'd suggest visiting my post SIBO 101: Signs & Associated Conditions.

Diagnosis of SIBO

The most common diagnostic method for SIBO is the breath test, which measures the levels of different gases produced after ingestion of a sugar solution, typically glucose or lactulose. These gases are produced when bacteria ferment the sugars, and the elevated levels can indicate bacterial overgrowth [1].

While glucose breath testing is more specific and results in fewer false positives, lactulose testing may detect overgrowth further down the small intestine. Recent advancements include Trio-smart breath test, a comprehensive test that measures hydrogen (H2), methane (CH4), and hydrogen sulfide (H2S) gases, providing a more complete gas profile. Proper test preparation and interpretation by a trained provider, are key for accuracy [3,4,5,6].

Additional diagnostic tools include [15]:

• Small bowel aspirate and culture - is considered the gold standard, though it is invasive and not widely available [2].

• Empirical treatment trials - utilized when testing is not available or results are equivocal.

Although empirical treatment may reduce testing-related costs, diagnostic testing with breath test is beneficial to guide the most effective treatment based on the specific type of gas that is elevated.

General Treatment Options for SIBO

Now that we understand the diagnostic methods, let's explore the treatment options available. Treatment for SIBO is usually multifaceted, involving:

1. Antibiotics

   Rifaximin is the most commonly used antibiotic due to its low systemic absorption and higher efficacy against hydrogen-producing bacteria. Methane-dominant SIBO may require the addition of neomycin or metronidazole [7,8].

2. Botanical Protocols 

   Using antimicrobial herbs such as oregano oil, berberine, allicin (from garlic), neem, and thyme have demonstrated comparable efficacy to rifaximin in clinical studies. These herbs exert broad-spectrum anti-microbial effects while also modulating inflammation and supporting gut integrity. A retrospective study found herbal protocols to be as effective as rifaximin for SIBO eradication in breath-tested patients, with fewer side effects and reduced recurrence in some cases. Integrative approaches may offer a gentler, long-term strategy for SIBO management, particularly in patients sensitive to pharmaceuticals [9,10,11].

3. Elemental Diet

   This diet is a specialized nutritional therapy involving a liquid-only diet for a certain period. The formula consists of amino acids, simple carbohydrates, and minimal fat, which are absorbed in the upper small intestine before they can be fermented by bacteria. This essentially starves the bacteria while providing easily absorbable nutrients to the patient. Studies have shown that the elemental diet can significantly reduce bacterial overgrowth and improve symptoms in as little as 14 days. It is often used when other treatments, such as antibiotics or herbal antimicrobials, are ineffective or poorly tolerated [12,13].

4. Dietary Interventions

   Restrictive diets such as the low FODMAP diet or the Specific Carbohydrate Diet (SCD) can help reduce symptoms by limiting fermentable carbohydrates that feed bacteria [14].

5. Pro-kinetics

   Medications like prucalopride or low-dose erythromycin as well as botanicals such as ginger are usually used after antibiotic therapy and in some cases as a stand-alone treatments to improve intestinal motility and prevent recurrence [9,15].

6. Nutritional Support

   This is to address vitamin and mineral deficiencies commonly seen in SIBO patients through supplementation, especially B12, iron, and fat-soluble vitamins [15].

7. Treatment of Underlying Conditions

   Long-term management requires addressing the root causes, such as hypothyroidism, motility disorders, inadequate digestion, low stomach acid, or anatomical abnormalities.

   
   

Final Thoughts SIBO can be a complex and frustrating condition, but with the right diagnosis and a personalized treatment plan, lasting relief is possible. Understanding the various testing options and treatment approaches can empower you to take meaningful steps toward healing. If you suspect SIBO is affecting your health, working with a qualified healthcare provider trained in treating SIBO is key. Remember, addressing the root cause of your symptoms is the first step to restoring balance in your gut and reclaiming your well-being.

Disclaimer: The information provided in this article is for informational and educational purposes only and is not intended as medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider before making changes to your diet, lifestyle, or health care regimen.

References

1. Rezaie A, Buresi M, Lembo A, et al. Hydrogen and methane-based breath testing in gastrointestinal disorders: The North American Consensus. Am J Gastroenterol. 2017;112(5):775-784. doi:10.1038/ajg.2017.46

2. Khoshini R, Dai SC, Lezcano S, Pimentel M. A systematic review of diagnostic tests for small intestinal bacterial overgrowth. Dig Dis Sci. 2008;53(6):1443-1454. doi:10.1007/s10620-007-0055-2

3. Ghoshal UC, Srivastava D. Irritable bowel syndrome and small intestinal bacterial overgrowth: Meaningful association or unnecessary hype. World J Gastroenterol. 2014;20(10):2482–2491. doi:10.3748/wjg.v20.i10.2482

4. Pimentel M, Saad RJ, Long MD, Rao SSC. ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth. Am J Gastroenterol. 2020;115(2):165–178. doi:10.14309/ajg.0000000000000501

5. Rezaie A, et al. Methane Producing Bacteria in Humans: A Review of Current Understanding. Clin Transl Gastroenterol. 2022;13(1):e00422. doi:10.14309/ctg.0000000000000422

6. trio-smart. About Trio-smart®. https://triosmartbreath.com/about. Accessed June 2025.

7. Bhatia M, et al. Treatment of small intestinal bacterial overgrowth: a systematic review. World J Gastroenterol. 2016;22(36):8199-8211. doi:10.3748/wjg.v22.i36.8199

8. Pimentel M, Fadul R, Lembo A. Rifaximin therapy for IBS: A review of clinical efficacy and safety in the target population. Ther Adv Gastroenterol. 2020;13:1756284820912976. doi:10.1177/1756284820912976

9. Langmead L, Rampton DS. Review article: herbal treatment in gastrointestinal and liver disease—benefits and dangers. Aliment Pharmacol Ther. 2001;15(9):1239-1252. doi:10.1046/j.1365-2036.2001.01078.x

10. Hu ML, Rayner CK, Wu KL, et al. Effect of ginger on gastric motility and symptoms of functional dyspepsia. World J Gastroenterol. 2011;17(1):105-110. doi:10.3748/wjg.v17.i1.105

11. Mullin GE, et al. Herbal therapy is equivalent to rifaximin for the treatment of small intestinal bacterial overgrowth. Global Adv Health Med. 2014;3(3):16-24. doi:10.7453/gahmj.2014.019

12. Pimentel M, Constantino T, Kong Y, Bajwa M, Rezaie A. A 14-day elemental diet is highly effective in normalizing the lactulose breath test. Dig Dis Sci. 2004;49(1):73-77. doi:10.1023/B:DDAS.0000011605.43916.41

13. Ruscio M, Smith B. The elemental diet: A novel treatment modality for small intestinal bacterial overgrowth. Pract Gastroenterol. 2013;XXXVII(8):20-26.

14. Staudacher HM, Irving PM, Lomer MCE, Whelan K. Mechanisms and efficacy of dietary FODMAP restriction in IBS. Nat Rev Gastroenterol Hepatol. 2014;11(4):256-266. doi:10.1038/nrgastro.2013.259

15. Quigley EMM. Small intestinal bacterial overgrowth: Roles of antibiotics, prebiotics, and probiotics. Gastroenterology. 2019;156(6):1515-1519. doi:10.1053/j.gastro.2018.12.019

©2025 by Nazanin Safaei, ND, MS