Key Advantages

  • Simple, non-invasive breath test

What is SIBO?


Normally, bacteria are found in the trillions in the LARGE INTESTINE, where they perform various symbiotic functions for the human body. SIBO is a condition where bacterial overgrowth occurs in the absorptive area of the body the SMALL INTESTINE.

  • The breath test is a simple, non-invasive test. After a 24 hours preparatory diet, the lactulose (or glucose or fructose) test substrate is swallowed.
  • Lactulose is not absorbed and therefore may act as a food source for bacteria, if present, in the small intestine.
  • The bacteria may ferment the lingering substances and produce hydrogen and/or methane. These gasses may then be diffused into the bloodstream and exhaled via the breath.
  • Breath samples are collected every 20 minutes for 3 hours.
  • All tests use machines from QuinTron, the original manufacturer of BreathTracker, to measure both hydrogen and methane in a single sample of breath (alveolar air).
  • Extensive quality control, including carbon dioxide measurements to assure an acceptable alveolar air sample, comply with the highest standards of analytical excellence. 


  • Diarrhoea
  • Constipation
  • Alternating constipation and diarrhoea
  • Abdominal cramping
  • Bloating and/or wind
  • Burping and Acid Reflux/GORD
  • Food sensitivities
  • Joint pain
  • Skin rashes
  • Iron and B12 deficiency
  • Respiratory symptoms such as asthma

SIBO can occur when:

The ileocecal valve (which connects the large and the small intestine) is dysfunctional, allowing large intestinal bacteria to migrate upwards into the small intestine, where they wreak havoc.

The normal cleansing wave of the small intestine is disrupted, or stopped. This cleansing wave is called the Migrating Motor Complex (MMS), and occurs approximately every 90 minutes, typically between meals. The function of the MMC is to wash out accumulated bacteria and propel them toward the colon. The MMC is not related to the peristaltic waves of the large intestines.

The result is bacteria are allowed to grow and proliferate throughout the small intestine (a little over 6 meters in length).

Effects of SIBO

SIBO causes damage to the absorptive surface of the small intestine – the ability of the body to absorb nutrients from food.

The absorptive surface of the small intestine is likened to a shaggy carpet, with finger-like protrusions called villi. The surface of the villi contain microvilli, which act as the interface of absorption—microvilli secrete enzymes called “brush border enzymes” which break starches into single molecules and proteins into single amino acids, so these can be absorbed.

Small Intestine – absorbing nutrients from food

SIBO can result in:

  • Malabsorption of monosaccharides and amino acids (carbohydrates and proteins)
  • Fermentation of disaccharides by bacteria causing hydrogen, methane and hydrogen sulphate gasses
  • These gasses themselves are damaging to the gut wall
  • Malabsorption of vitamins (especially B12 and Folic acid)
  • Malabsorption of minerals (especially, magnesium, iron, and calcium SIBO can cause leaky gut, with a damaged gut wall allowing larger particles to pass through, causing an immune response

Causes of SIBO:

  • Post infectious: a case of gastroenteritis can often be the “heralding event” for the development of SIBO
  • Overconsumption of simple carbohydrates
  • Medications: proton pump inhibitors, morphine and other opiates, narcotics, possibly beta agonists and calcium channel blockers
  • Stress: chronic stress can decrease stomach acid output (hypochlorhydria).
  • Normal stomach acid levels are required to kill bacteria
  • Stress also causes changes in the motility of the small intestines, causing a pooling and stagnation which allows for bacterial overgrowth
  • Altered anatomy: malformation of the ileocecal valve, surgical intervention causing scarring and adhesions altering the normal anatomy of the small intestines
  • Initial colonization of bad bacteria: caesarean birth, no breast feeding

Available Tests

SIBO BASIC: Lactulose Only

SIBO ADVANCED: Lactulose + Glucose

SIBO COMPREHENSIVE: Lactulose + Glucose + Fructose


If you have been authorised a test by your practitioner, or would like more information on how to conduct your functional test click HERE  If you already have a Research Nutrition account, please log in below.

If you do not have an account and would like to sign up for one, you can do so online HERE

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ResourcesVideo: What is SIBO?PreparationFree WebinarPatient SupportTest PricingOrdering

Important: 24 hours (48 hours if you are constipated) before you start the test, you MUST restrict certain foods. You must also avoid certain medications and supplements for a minimum of 1 week.

Refer to the collection instructions for the full preparation guide.

SIBO Assessment, Treatment, and Management

In this webinar, Dr Nirala Jacobi will cover the common underlying factors, proper breath testing assessment and interpretation, and summarise treatment options.

A video to assist patients on how to collect their sample and other FAQs on this test can be found via the Patient Resources section of this site.

For up-to-date prices on all tests please refer to the Authorise a Test Form

  • Research Nutrition operate a Functional Testing Patient Order System where you can Authorise a Test for your patients online. See our Online Authorisation Guide or watch the video below for more information.

  • Alternatively you may prefer to use our Paper Authorisation System. See our Paper Authorisation Guide for more information.
  • If you would like to order a test kit for your clinic, please contact us directly for more information.