top of page


SIBO, short for small intestinal bacterial overgrowth, affects thousands of Americans every year. Much like the name suggests, it’s a disorder caused by the presence of otherwise normal colonic flora growing in the wrong location - your small intestines. Issues arise when the gasses produced by this flora impact the small intestine’s enteric nervous system, resulting in changes in movement and increased sensitivity to pain, among other concerns like gas and bloating. ​SIBO is a non-threatening but annoying condition that often causes long-standing issues if left without treatment. Learning you have SIBO can often be both a worry and a relief, as it provides some direction as to the underlying cause of your otherwise ‘IBS’ labelled symptoms. But what happens when you present with all the symptoms of SIBO, but your breath test results come back negative? Is that the end of the road for the microbiome's role in your gut issues? ​

What Is SIBO? Your colon is currently hosting bacteria in large quantities to help break down food and absorb nutrients, even as you read this article. SIBO refers to these same organisms crowding in your small intestines, leading to irregular stools like diarrhea or constipation, gas, bloating abdominal pain and sometimes even belching and acid reflux. SIBO is generally categorized into either a hydrogen-dominant or methane-dominant overgrowth, however, today’s doctors have learnt there may be a third source of SIBO symptoms:

  • Methane-dominant SIBO, showing elevated CH4 gasses on a SIBO breath test and caused by methanogenic archaebacteria

  • Hydrogen-dominant SIBO, producing elevated H2 gasses on breath tests, often causing fast transit time and/or loose stools.

  • Hydrogen sulfide-dominant or H2S, also often produces loose stools but is much harder to detect (not visible on standard SIBO breath testing)

HS2 SIBO, methane dominant SIBO, and hydrogen dominant SIBO have correlational symptoms, but the most common symptoms include:

  • Bloating

  • Acid reflux

  • Chronic abdominal pain

  • Belching

  • Constipation

  • Diarrhea

  • Bladder pain

Secondary symptoms such as joint pain, brain fog and fatigue are also commonly reported. Hydrogen sulfide overgrowth also uniquely may present with very malodorous gas and bad breath. Testing for Hydrogen Sulfide SIBO Your physician will rule out other infectious and gastrointestinal disorders before diagnosing you with a SIBO. A lactulose breath test is used to do this - involving ingesting a non-digestible sugar solution that produces methane and hydrogen sulfide gas as gut bacteria ferments it. If these gasses spike quickly into testing, it's a telltale indicator of a SIBO diagnosis. However, when a SIBO breath test shows negative results, it doesn't confirm that a hydrogen sulfide overgrowth has been ruled out, as breath testing (to date) is not readily available for this type of gas. The Trio-Smart test, which has been developed in collaboration with SIBO researcher Dr. Mark Pimental, does have the potential for H2S diagnosis, but has yet to be adopted as a gold standard diagnostic technique and is not yet available in Ontario at the time of this article. While not as reliable as breath, stool testing is sometimes necessary to detect the presence of hydrogen sulfide flora. According to clinical data, people with IBS and poor gut health are twice as likely to test positive for SIBO than the average person. Related health conditions associated with SIBO also include rosacea, fibromyalgia, ulcerative colitis, hypothyroidism, metabolic disorders, and arthritis - however, there is still a lack of data to confirm if the treatment of SIBO can resolve these conditions. Hydrogen Sulfide SIBO Treatment While H2S SIBO is often treated similarly to SIBO with antimicrobials, the therapies chosen are often different, as bacterial resistance occurs with many of the traditional first-line SIBO interventions and can often be why patients experience partial or minimal recovery from SIBO treatment. Important adjunctive therapies to integrate for success still include biofilm management and strain-specific probiotics alongside antimicrobial treatments. Furthermore, while many SIBO treatments no longer recommended restrictive diets, hydrogen sulfide overgrowths will see more significant symptomatic improvements from a low-sulfur diet and will be driven by the intake of certain fructooligosaccharides and sugar alcohols. Lastly, if you suspect that you have SIBO, get a proper diagnosis before proceeding with a treatment program. Accuracy of therapies, as well as a proper diagnosis, can save time and headaches, as well as your good microbiota, down the road. To learn more about SIBO, proper diagnostic assessments, and accurate treatment options, please contact Toronto Naturopathic Doctor, Dr. Courtney Holmberg at 647-351-7282 to schedule your appointment today.

1 comentario

Obtuvo 0 de 5 estrellas.
Aún no hay calificaciones

Agrega una calificación
21 dic 2023

SIBO may be merely annoying for some, but for many of us it has devastating, life-limiting impacts.

Me gusta
bottom of page