What is SIBO?
Small Intestinal Bacterial Overgrowth (SIBO) is a condition in which there is an increase in the number or type of bacteria in the small intestine. These bacteria ferment the simple carbohydrates we consume in food. This overgrowth causes detrimental effects to the gastrointestinal system, as well as to systemic health.
What are the symptoms of SIBO?
The most common symptoms associated with SIBO are related to GI upset, especially gas and bloating, abdominal pain, nausea and chronic constipation, diarrhea or the alternating of both. SIBO symptoms very closely match up with what is often considered an IBS diagnosis. In fact, a review in 2014 and recent clinical research at Cedars-Sinai Medical Center estimates that over 80% of IBS diagnoses are likely related to SIBO (1). There are some more unique symptoms that may be suggestive of SIBO, but are not always present in every case. This includes: intolerance to high-fiber diet (people who are constipated get worse when consuming fiber), aggravation of GI symptoms with prebiotics or probiotics, and temporary improvements to GI symptoms with antibiotics followed by relapse. There are also a number of conditions that have been associated with an increased likelihood of also having SIBO, including rosacea (2), achlorhydria (low stomach acid) (3), arthritis (4), immunodeficiency and auto-immune disorders (3). If SIBO is chronic and persistent, it can have long-term impacts on nutrient absorption, potentially causing malnutrition and weight loss.
There are various questionnaires available for rating symptoms to assess likelihood of having SIBO. These questionnaires can be useful as part of a comprehensive approach for evaluating a patient, but are by no means diagnostic on their own. A sample questionnaire is available ***here***
What causes SIBO?
Many correlations and associations have been drawn between certain factors and the pathogenesis of SIBO, though what causes it exactly is still not completely understood. A common theory is that a disruption of the migrating motor complex (MMC) of the gut alters the natural functional movement of the intestines, allowing for bacteria to “build up” in the small intestine. Many things can impact the MMC function (positively and negatively), including prescription drugs, abdominal surgery, food poisoning, and chronic GI disorders like IBD and celiac disease. Because the MMC functions through nerve transmission, other conditions seemingly not related to the GI can still impact it, like neurologic disorders and even mood disorders like anxiety and depression. As such, there are a diverse number of potential causes for developing SIBO and part of an accurate diagnosis is a thorough review of the patient’s medical history.
How is it tested?
The gold-standard for testing SIBO for decades has been a small bowel aspirational biopsy with culture. There are many reasons why this may not be the best method for diagnosis. For one, it is an invasive surgical procedure. In fact, many gastroenterologists do not perform the procedure at all, so it is not even a widely-available means of diagnosis. Also, the rate of false-positives can be very high with this test as samples are only taken from one or a few specific spots in the small intestine (that is over 20 feet long); we know that SIBO can form in “patches” and thus the chance of simply missing the affected area during aspiration collection using this technique is quite possible. Lastly, there is a significant expense associated with this type of procedure. Because of these obstacles, while SIBO has been an accepted medical diagnosis for many years, it has been under-reported and under-diagnosed for a long time.
In recent years, gas analyzer technology has been better developed for medical diagnostic purposes which has led to a newer, more widely-available and accessible way of diagnosing SIBO through the use of breath testing. Breath testing uses our knowledge of the bacterial fermentation of carbohydrates in SIBO to identify whether a patient has an overgrowth or not. Lactulose is not absorbed by the human GI tract and so it is used as the carbohydrate substrate in breath tests as it should pass through the length of the gut, allowing it to be fermented by any SIBO anywhere, if present. When the lactulose is fermented by the bacteria, they produce gases that are absorbed into the blood stream and excreted in our breath. The breath test measures the levels of these gases that the patient breathes out after consuming a lactulose sample. Elevations in the gases, as well as how long after the consumption of the lactulose the elevations occur, can not only diagnose the presence of SIBO, but can also suggest what types of bacteria are predominantly involved in that case. It is a more sensitive test than aspirational biopsy, because breath testing allows us to evaluate the entire length of the GI for the presence of SIBO, not just specific areas (while neglecting others) as with an aspirational biopsy.
The American Journal of Gastroenterology published consensus statements regarding breath testing in May 2017, concluding that breath testing is indicated for the diagnosis of SIBO and is a useful, inexpensive, simple and safe diagnostic test (5).
Breath testing can be performed by the patient in the comfort of their home. The test-kit and procedure instructions are very user-friendly and safe. A preparation diet and overnight fasting is recommended before performing the test. A baseline sample is first collected, then the lactulose solution is consumed and breath samples are collected every 20 minutes over 3 hours. There is the possibility that the patient’s GI symptoms will be aggravated by the test transiently. The samples are then processed and analyzed using a Quintron Gas Analyzer device. Results are recorded numerically and also plotted on a graph for the ordering practitioner and patient.
Lokahi Health Center is the only institution in the state of Hawaii that offers SIBO lactulose breath testing using this gas analyzer technology in-house. We offer breath testing ordered by other practitioners to their patients with requisition. Our test-kits can be sent to any clinic or directly to patients and includes pre-paid return shipping. We guarantee a 7-day turnaround for results once the completed test-kit has been received at our clinic. The current testing cost is $180 USD + tax.
For test requisition forms, please click HERE. For more information, please contact us at lokahihealth@gmail.com or by phone at 808-329-2114.
How is it treated?
There are well-established approaches to treating SIBO, most of which have shown comparable effectiveness to one another in clinical trials (6). SIBO treatment also typically falls into phases: reducing bacterial overgrowth, maintenance and repair. Reducing the bacterial overgrowth can be achieved through specific dietary modifications, certain prescription antibiotics or antimicrobial herbs or a combination of all approaches. Maintenance and repair phases are usually a combination of dietary strategies and prokinetic medications (that improve the motility of the small intestine) to address the underlying causes of the problem and reduce the chance of relapse. Within each of these therapeutic categories, there are a number of different options to select from. Choosing the right treatment for a patient takes into consideration a number of factors, including addressing underlying causes, their specific SIBO test results, their previous medical history and their primary symptoms. This allows us to personalize a treatment plan that is specific to the patient, to ensure the best outcomes for that individual case. Every SIBO case is different and response to treatment and length of treatment required for recovery can vary significantly. Ensuring patients are being managed by an expert in SIBO maximizes chances of receiving optimal treatment and definitive resolution.
For more details, A Clinician’s Guide to the Evaluation and Treatment of SIBO (sponsored by Quintron Instrument Company and published in the Natural Medicine Journal) is available here.
References:
- 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
- Parodia A, Paolino S, Greco A et al. Small Intestinal Bacterial Overgrowth in Rosacea: Clinical Effectiveness of Its Eradication. Clinical Gastroenterology and Hepatology. 2008;6(7):759-764. doi:10.1016/j.cgh.2008.02.054
- Bures J. Small intestinal bacterial overgrowth syndrome. World J Gastroenterol. 2010;16(24):2978. doi:10.3748/wjg.v16.i24.2978
- Henriksson A, Blomquist L, Nord C, Midtvedt T, Uribe A. Small intestinal bacterial overgrowth in patients with rheumatoid arthritis. Ann Rheum Dis. 1993;52(7):503-510. doi:10.1136/ard.52.7.503
- Rezaie A, Buresi M, Lembo A et al. Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus. American Journal of Gastroenterology. 2017;112(5):775-784. doi:10.1038/ajg.2017.46
- Chedid V, Dhalla S, Clarke JO, et al. Herbal therapy is equivalent to rifaximin for the treatment of small intestinal bacterial overgrowth. Glob Adv Health Med. 2014;3(3):16-24. Doi: 7453/gahmj.2014.019