Small Intestinal Bacterial Overgrowth (SIBO)

Small Intestinal Bacterial Overgrowth (SIBO) is a prevalent digestive condition that occurs when there is excessive bacteria within the small intestines and commonly contributes to a range of digestive and systemic symptoms. Common digestive symptoms include bloating and abdominal pain after eating and chronic diarrhoea and/or constipation. Persisting digestive issues may then contribute to nutrient deficiencies due to poor absorption – such as iron and vitamin B12, and carbohydrate malabsorption – including fructose and lactose malabsorption. SIBO can also contribute to a range of symptoms beyond the digestive system. These include fatigue, ‘brain fog’ and poor concentration.

A range of factors can contribute to the development of SIBO. These include:

  • Motility Issues, such as gastroparesis and chronic constipation
  • Irritable Bowel Syndrome
  • Metabolic Disorders, such as diabetes and hypothyroidism
  • Medications; such as antibiotics and proton pump inhibitors
  • Renal Failure
  • Coeliac Disease
  • Chronic Stress
  • Infections and Traveller’s Diarrhoea
  • Exposure to Mould Biotoxins

The main diagnostic tests for SIBO is Glucose and Lactulose Hydrogen Methane Breath Testing. The most common test for SIBO in Australia is using Glucose as the test substrate and Lactulose only as a marker of transit time. However, the North American Consensus indicates that Lactulose is also appropriate for diagnosing SIBO. SIBO positive results on a glucose test generally indicate an overgrowth of bacteria in the proximal small intestine (the upper part of the small intestines), whilst SIBO positive results on a lactulose test indicates bacterial overgrowth of the distal small intestines (the lower part of the small intestines). In addition to testing via glucose and lactulose, it is important to measure both hydrogen and methane production during testing. However, not all labs in Australia record methane, which leaves the possibility of missing a positive diagnosis at times.

Beyond breath testing, microbiome testing can be useful in identify the types of bacteria that are involved and whether fungal overgrowth is also likely to be present, as this is not screened for in breath tests. There are a range of tests available for microbiome assessment, and therefore, choosing the most appropriate one for your presenting symptoms is key.

If you suspect you may be suffering from SIBO, the best thing to do is book a naturopathy appointment to discuss present health issues and look at what type of investigations suit your unique presentation. With results, a targeted treatment protocol can be developed to clear SIBO and/or fungal overgrowth. This typically includes dietary modification, the use of antimicrobial herbs to clear bacterial and/or fungal overgrowth, probiotics, and nutritional supplements. Once SIBO is clear, treatment shifts to a maintenance plan that aims to reintroduce foods and support growth of beneficial bacteria to ensure relapse does not occur.

If you’re ready to tackle SIBO and improve energy, sleep, cognition, and gut function, book an appointment today.

References

  1. Rezaie et al., 2017, Hydrogen and Methane-Based Breath Testing In Gastrointestinal Disorders: The North American Consensus, The American Journal of Gastroenterology, March 2017, pp. 1-10.
  2. Grace et al., 2013, Review article: small intestinal bacterial overgrowth – prevalence, clinical features, current and developing diagnostic tests, and treatment, Alimentary Pharmacology and Therapeutics, 38, pp. 674-688.