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SIBO – What is it?


What is Small Intestinal Bacterial Overgrowth (AKA SIBO)

SIBO occurs when bacteria which normally reside in the large intestine, migrate into the small intestine, which can lead to gastrointestinal symptoms similar to IBS as well as systemic symptoms. The bacterial accumulation in the small intestine is not pathogenic bacteria, but rather normal gut flora which has made its way from the large intestine to the small intestine which could be due to various reasons.

Research suggests that SIBO may be the underlying cause of IBS in many cases.  

Digestive symptoms may include:

  • Abdominal pain
  • Abdominal distension
  • Bloating
  • Diarrhoea
  • Flatulence
  • Cramping
  • Constipation
  • Reflux

These symptoms occur as a result of the high osmotic activity and fermentation potential of incompletely digested and unabsorbed carbohydrates (such as FODMAPs) present in the small intestine.

Systemic symptoms may include:

  • Fatigue
  • Weight loss / weight gain
  • Concentration loss
  • Steatorrhoea
  • Nutritional deficiencies (vitamin B12, iron, calcium, magnesium, fat-soluble vitamins)

Potential causes of SIBO:

  • Anatomical abnormalities (abdo surgery)
    • Low stomach acid – long term use medications such as PPIs, narcotic medications & from ageing
    • Bile & Enzyme Deficiencies
    • Poor motility-  slow functioning of the MMC
    • Ileocecal Valve Malfunction- the valve between the small intestine and large intestine (colon) that prevents movement of bacteria from the large intestine into the small intestine.
    • Immunodeficiency syndrome – disorders that supress the immune system (AIDS / IgA antibody deficiency)
    • Coeliac disease
    • Alcoholism – chronic consumption appears to increase risk
    • Gastroparesis – overlap in symptoms and those with gastroparesis appear more likely to have SIBO

Diagnosing SIBO:

Hydrogen-Methane Breath Tests are commonly used to diagnose SIBO. There are two types of breath tests used- Lactu-lose Breath Tests and Glucose Breath Tests. Both of these tests measure the concentration of hydrogen and methane in the breath. Malabsorption occurs when a large amount of hydrogen or methane is produced (by bacteria) in the first two hours or so after ingesting the sugar. This indicates that SIBO is present as fermentation should not be occurring this early on in the gastrointestinal tract. However, the accuracy and validity of these breath test results is not clear. Here at Stream Diagnostics we can test for SIBO using our Hydrogen-Methane Breath testing. If you want to know more about this test and see if it’s right for you, give us a call today!