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What is Small Intestine Bacterial Overgrowth (SIBO) and What Do I Do About it?

With researchers uncovering the significant impact of the microbiome on our overall well-being, gut health has been all the rage in recent years. Small Intestine Bacterial Overgrowth (SIBO) is a condition that's often over looked and mistakenly diagnosed as IBS. In this blog post, I'll delve into what SIBO is, how to find out if you have it, common symptoms, and treatment options.

What is Small Intestine Bacterial Overgrowth (SIBO)?

Small Intestine Bacterial Overgrowth, or SIBO, is a gastrointestinal condition characterized by an excess amount of bacteria in the small intestine. It's thought that up to 84% of patients with IBS have SIBO. The good news is that SIBO is both testable and treatable. If you have received a diagnosis of IBS it may be worth seeking out a SIBO test.

Common Causes of SIBO

  • Intestinal dysmotility (? hypothyroidism ? post-concussion syndrome)

  • Hypochloremia caused by chronic proton pump inhibitor (PPI) use

  • Reduced pancreaticobiliary secretions caused by chronic pancreatitis

  • Ileocecal valve impairment

  • Adhesions and strictures

  • Gastroparesis

  • Gastric bypass

  • Chronic opioid use

How is SIBO Diagnosed?

SIBO can be diagnosed either by a small bowel aspirate culture showing ≥103 colony-forming units (CFU) per mL of aspirate, or a positive lactulose or glucose breath test.

A small bowel aspirate culture involves obtaining a fluid sample from your small intestine, and is the gold standard for diagnosing SIBO. The invasive nature of this test is thought to be one of the reasons SIBO is under-diagnosed.

Breath testing is noninvasive and easier to access option than a small bowel aspirate culture. The test involves following a non-fermentable diet for 24 hours, and then drinking a mixture of glucose or lactulose and water and breathing into a tube multiple times over a 2-3 hour timespan. You can take this test at home, a doctor's office, or laboratory.

If you have SIBO the bacteria in your small intestine will ferment the sugars you drank and produce hydrogen, methane, or hydrogen sulphide gas. The test measures the amount of gas produced and will provide your doctor with the information they need to make a diagnosis.

Common Symptoms of SIBO:

The manifestations of SIBO can vary, but common symptoms include:

  • Abdominal distention

  • Abdominal pain

  • Belching

  • Flatulence (gas)

  • Diarrhea

  • Constipation

  • Anemia

  • In extreme cases, signs of malnutrition and weight loss

Hydrogen and hydrogen sulphide gases are more likely to cause diarrhea, and methane gas is more likely to cause constipation.

What Can I Do To Fix SIBO?

Once you've been diagnosed with SIBO, you can work with your doctor and a Registered Dietitian and/or naturopath to craft an effective treatment plan. Common approaches to managing SIBO include:

  • Dietary Modifications: There are a number of dietary strategies that can be used to reduce bacterial overgrowth, they often involve limiting fermentable carbohydrates. Examples include: the Low FODMAP diet, The Specific Carbohydrate Diet (SCD), Cedars Sinai Diet, Bi-phasic Diet, Elemental Diet.

  • Antibiotics: Certain antibiotics, such as rifaxmin, are effective in reducing bacterial overgrowth in the small intestine. However, antibiotics will not address the underlying cause of SIBO; you will want to work with a practitioner to identify the root cause so that it does not come back.

  • Probiotics: Introducing beneficial bacteria through probiotic supplements can help rebalance the microbiome in the gut, reducing the risk of SIBO recurrence. However, not all probiotics are created equal, talk to a dietitian or naturopath about choosing the right probiotic for you.

  • Lifestyle Changes: Adopting a healthy lifestyle, including stress management techniques, regular exercise, and adequate sleep, can contribute to the overall success of SIBO treatment.

Let's Get Started!

Have the symptoms of SIBO or better yet a diagnosis? Book a discovery call with me today and we can get started on your personalized path to symptom relief. Changing your diet can be overwhelming and stressful and supplements are expensive, if you're going to treat SIBO do it right the first time. Tackling SIBO is not something you want to do alone!


Spiegel, Brennan. Questioning the Bacterial Overgrowth Hypothesis of Irritable Bowel Syndrome: An Epidemiologic and Evolutionary Perspective. 2011 March 14. DOI:

Pimentel Mark. Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome – An Update, Volume 11. 2020. DOI=10.3389/fpsyt.2020.00664

Achufusi TGO, Sharma A, Zamora EA, Manocha D. Small Intestinal Bacterial Overgrowth: Comprehensive Review of Diagnosis, Prevention, and Treatment Methods. Cureus. 2020 Jun 27;12(6):e8860. doi: 10.7759/cureus.8860. PMID: 32754400; PMCID: PMC7386065.

Rezaie A, Buresi M, Lembo A, Lin H, McCallum R, Rao S, et al. Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus. Am J Gastroenterol (2017) 112(5):775–84. doi: 10.1038/ajg.2017.46


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