Small Intestinal Bacterial Overgrowth (SIBO)
This article was written by Kaitlin Colucci, Founder of the KC Nutrition Clinic.
What is SIBO?
SIBO occurs when there is an increase in the number, or abnormal type, of bacteria living in the small intestine. Normally, gut bacteria live in the large intestine and make up the community of trillions of bacteria known as the gut microbiota. In the small intestine, the bacteria have access to all sorts of food they don't normally have access to in the large intestine, causing fermentation in a part of the gut which is a lot more sensitive to this fermentation.
Symptoms
Symptoms of SIBO closely mirror those of IBS. The most common symptoms of SIBO are:
Bloating within 1 hour after meals
Diarrhoea or constipation or alternating between the two
Burping or reflux after meals
Foul smelling gas
Stomach gurgling and discomfort or cramping
Secondary symptoms that accompany the most common symptoms of SIBO can include:
Restless legs at night
Multiple food sensitivities
Brain fog
Chronic iron and/or B12 deficiency
Weight gain or loss
Difficulty sleeping
Another symptomatic clue might be that digestive symptoms improve while using antibiotics, even for unrelated issues.
How to test for SIBO
The ‘gold standard’ for non-invasive SIBO testing is a lactulose and/or glucose breath test that measures the levels of hydrogen and methane gas in your breath.
Why you may not have SIBO despite a positive SIBO test result?
Lactulose breath tests can often give a false positive result, especially in those with a shorter intestine or faster transit time. If the lactulose makes its way through the small intestine faster than expected, then you’ll likely get a false increase in gas production.
This is why it's so important to have a trained and qualified practitioner interpret your results based on your symptoms and medical history, as results can't always be taken for face value.
Treatment options
Dietary change in the form of a low FODMAP diet
Theory: 'starves' or underfeeds the overgrowing bacteria in the small intestine. Also helps to identify any specific dietary triggers for symptoms. Can be a helpful route to take given the risk of false positive results, and symptoms likely being due to IBS.
Antibiotic treatment
Theory: 'kills off' the overgrowing bacteria in the small intestine. Rifaximin is the most common antibiotic used in the treatment of SIBO.
Other options
Other options do exist for the treatment of SIBO if the above two have failed to bring about any satisfactory relief of symptoms. However these should be discussed with a registered dietitian and/or gastroenterologist with specialist knowledge in the diagnosis & treatment of SIBO.
At the KC Nutrition Clinic, we are a team of Registered Dietitians with specialist knowledge in the area of lactulose & glucose breath test interpretations, as well as the diagnosis and treatment of SIBO.
If you are suffering & need help reviewing your diet, book in to speak to a dietitian at the KC Nutrition Clinic with either Kaitlin or Annabel.