SIBO (Small Intestinal Bacterial Overgrowth)

Normally the human small intestine is sparsely colonised by bacteria in comparison to the colon. Structural or functional disorders of the gastrointestinal tract can lead to bacterial overgrowth in the small intestine, with colonic bacteria proliferating in the ileum and jejunum. Small intestinal bacterial overgrowth (SIBO), as it is known, is characterized by steatorrhea and diarrhoea, together with vitamin deficiencies and carbohydrate malabsorption as the overgrowth causes damage to the absorptive surface of the intestine. The syndrome is difficult to diagnose with accuracy using blood tests.

Bacteria growing in the intestine can break down carbohydrates to produce hydrogen and methane, which are rapidly transported to the lungs via the portal blood supply and the liver. The sole source of these gases in alveolar air is bacterial fermentation of carbohydrate in the gut, so estimation of hydrogen and methane in breath samples can be used to study the passage of carbohydrates through the gut and the presence of pathogenic bacteria in the gastro-intestinal lumen.

Uncover the Cause of Unexplained Abdominal Symptoms with Breath Testing

SIBO is a common clinical condition and can develop in a variety of patient populations.Our Clinic’s SIBO Profiles are non-invasive breath tests which capture exhaled hydrogen (H2) and methane (CH4) gases following patient ingestion of a lactulose solution to evaluate bacterial overgrowth of the small intestine. Levels of Carbon Dioxide (CO2) are also measured in every sample for quality control purposes.

We, as Clinicians now have the option of a 2 or 3-hour SIBO assessment.

The 3-hour SIBO profile provides insight into gas levels over a longer period of time, and is recommended for patients with slower gastrointestinal transit or constipation.

When should testing for SIBO be considered?

Symptoms of SIBO are non-specific, encompassing abdominal pain/distention, diarrhoea, and flatulence.

Conditions commonly associated with SIBO include:

  • IBS
  • IBD
  • Coeliac Disease
  • Diabetes
  • Fibromyalgia
  • Rosacea
  • Parkinson’s Disease
  • Obesity

Risk factors for development of SIBO include structural/anatomic issues, motility disorders, organ system dysfunction, elderly age and various medications (recurrent antibiotics, PPIs) that alter the gut microflora populations.

What advantage does the SIBO breath test offer compared to other diagnostics?

While aspiration of small bowel fluid (followed by culture and bacterial count) is considered to be the current gold standard for diagnosis of SIBO, it is not routinely performed because it requires a complex, invasive technique, and is costly. As a result, experts suggest breath testing for the diagnosis of small intestinal bacterial overgrowth.

What can clinicians and patients expect from the SIBO breath testing?

In general, clinical management of the SIBO patient involves antimicrobial therapy, prokinetic agents, nutrient supplementation, dietary interventions, and treatment of comorbid conditions.

Our Clinic’s SIBO profiles reflect the current state of scientific understanding related to SIBO breath testing and results interpretation – and are designed to optimise management of the symptomatic patient.

Test Type: Breath Test