SIBO, short for small intestinal bacterial overgrowth, affects thousands of Americans yearly. 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 movement changes 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, providing some direction for 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 microbiome’s role in your gut issues? Learning you have SIBO can often be both a worry and a relief, we will discuss about a comprehensive guide to hydrogen sulfide

Hydrogen Sulfide

What Is SIBO?

Your colon currently hosts large quantities of bacteria 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 produces elevated H2 gasses on breath tests, often causing fast transit time and/or loose stools.
  •  Hydrogen sulfide-dominant or H2S often produces loose stools but is much harder to detect (not visible on standard SIBO breath testing) .

SIBO Symptoms

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.

Effects of SIBO

The bacteria that cause hydrogen sulfide SIBO produce hydrogen sulfide gas inside the small intestine, hence the name. This side effect produces readily apparent symptoms that cause discomfort, namely gas and bloating, but also less obvious symptoms like joint pain and brain fog.

The bacterial flora in your digestive tract forms a delicate and precarious balance. When the H2S bacteria spreads high in your small intestine, where they don’t belong, they interfere with proper digestion. This causes malabsorption, limiting the body’s ability to process and acquire the nutrients in foods and can lead to food rotting inside the digestive tract.

When the body fails to absorb carbohydrates, the overabundance triggers microorganisms in the gut to perform fermentation. Aside from the gaseous byproducts and the effects of alcohol in your system, fermentation also damages the intestinal tract cells that control permeability in the intestines, leading to a condition known as “leaky gut” syndrome. Water, nutrients, and other substances leak through the permeable intestinal walls, setting off a series of reactions and inflammatory responses.

SIBO also limits gastrointestinal motility, which along with malabsorption and leaky gut syndrome, prevents the body from moving food through the digestive tract properly.

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.

Doctors use a simple breath test to identify the primary variants of SIBO, hydrogen and methane. However, the third variant, hydrogen sulfide SIBO, remains far harder to diagnose. Breath test results that identify SIBO may miss the hydrogen sulfide variant, so your doctor may require blood work and stool testing to confirm the diagnosis.

The Trio-Smart test, developed in collaboration with SIBO researcher Dr. Mark Pimental, has 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.

SIBO Comorbidity

SIBO often presents comorbidly with gastrointestinal disorders like inflammatory bowel disease and irritable bowel syndrome, meaning patients with these conditions carry a significantly higher risk of contracting SIBO. Studies report more than one-third of patients diagnosed with IBS also test positive for SIBO, making them almost five times more likely to test positive for SIBO than the general population.

Studies link SIBO with many debilitating conditions, including the following.

  •  Rosacea
  •  Diabetes
  •  Metabolic health conditions
  •  Coronary artery disease
  •  Ulcerative colitis
  •  Hyperthyroidism
  •  Rheumatoid Arthritis
  •  Fibromyalgia
  •  chronic pancreatitis
  •  Chronic kidney disease
  •  Parkinson’s disease

Hydrogen Sulfide SIBO Treatment

While H2S SIBO is often treated similarly to SIBO with antimicrobials, the therapies chosen are often different. 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. 

This means bacterial resistance increases complications for basic antibiotic regimens, limiting their effectiveness.

Important adjunctive therapies to integrate for success still include biofilm management, strain-specific probiotics, and antimicrobial treatments.

Balancing the types and locations of gut bacteria and repairing the optimal gut biome are the most effective treatment goals for all types of SIBO.

Furthermore, while many SIBO treatments no longer recommend restrictive diets, hydrogen sulfide overgrowths will see more significant symptomatic improvements from a low-sulphur diet and will be driven by the intake of certain fructooligosaccharides and sugar alcohols. 

Looking at the gut holistically offers the best approach to hydrogen sulfide SIBO treatment and other types of SIBO. Your digestive tract includes microbes that work with your body to break down food and absorb nutrients. This delicate biome includes many strains of bacteria ranging from beneficial to neutral to detrimental. In a healthy system, the beneficial bacteria work with your body to limit or neutralize detrimental strains while performing vital functions that promote digestion.

Lastly, if you suspect 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. 

Work with your doctor throughout treatment to adjust your diet to reduce intakes that impede your gut health. Promoting a strong and healthy gut biome helps you to heal from SIBO and to resist the recurrence of SIBO in the future.

To learn more about SIBO, proper diagnostic assessments, and accurate treatment options, please contact Naturopathic professional Doctor