What is SIBO?

Small Intestinal Bacterial Overgrowth or shortly SIBO is a digestive disorder when an increased amount of bacteria present in the small intestines. Bacteria start fermenting carbohydrates, starches, fibers and produce byproducts, gases, which can cause damage to the small intestines’ wall and lead to different symptoms. (1)

These symptoms could be: bloating and gas, diarrhea and/or constipation, abdominal pain, nausea, belching, reflux, rashes, food intolerances, and many more. The whole process would be normal if it occurred in the large intestine, where it is supposed to happen. (2)
While looking at the symptoms, we can’t say certainly which type of SIBO someone has, although you can guess.

Doing a SIBO lactulose or glucose breath test is one of the best and practical ways to identify it. (3) So test, don’t guess!

SIBO is categorized into different subtypes:

• Hydrogen Dominant SIBO
• Methane Dominant SIBO
• Hydrogen Sulfide Dominant SIBO

The main difference between these three types of SIBO is the gases produced by the bacteria residing in the small bowel. It is also possible that someone has a Mixed Type of SIBO, meaning multiple types of gases present simultaneously.

Hydrogen Dominant SIBO

The most common symptoms with the Hydrogen type of SIBO are diarrhea/loose stools, abdominal cramping, pain, bloating. Normal commensal bacteria in our intestines produce hydrogen gases through carbohydrate fermentation. Hydrogen could be a substrate for other gas production such as methane, acetate, and hydrogen sulfide. (2)(4)

The conventional approach for hydrogen-dominant SIBO includes antibiotics such as Rifaximin (Xifaxan). Rifaximin is a nonsystemic antibiotic, which has an effect on the small intestine. (5)(6)
A natural protocol uses single herbs or herbal complexes such as Berberine, Neem, Oregano.

Methane dominant SIBO / Intestinal methanogen overgrowth

It is more likely associated with constipation, nausea because methane slows down the intestinal transit, the way the food passes through the intestines and also causing retrograde motility (8). It is most commonly caused by Methanobrevibacter smithii (M. Smithii), which belongs to ancient archaea, single-celled organisms, and not bacteria. The higher amount of M. Smithii you have, the higher the chances you will have symptoms. Methanogens create methane in the body, and to do that, they require hydrogen and carbon dioxide. (7)
Methane dominant SIBO patients are mostly less reactive to foods than hydrogen dominant SIBO patients, although they respond to treatment much slower.
Not everyone with constipation or IBS-C has methane overgrowth.

Conventional treatment of methane overgrowth requires different and additional medication next to Rifaximin, e.g., Neomycin or Metronidazole. (9) The natural antimicrobial next to the herbs, as mentioned earlier, would be Atrantil, Allicin (stabilized garlic extract).

Hydrogen Sulfide SIBO

This type of SIBO is associated with belching, flatulence with the foul odor of rotten eggs, nausea, diarrhea or constipation, abdominal pain, body/joint pain, even bladder pain. Hydrogen Sulfide (H2S) gas is produced by sulfate-reducing bacteria that feed on hydrogen. (10)

Testing Hydrogen sulfide SIBO can be tricky. The only test that can diagnose this type is the TrioSmart test that is only available in the US.

According to Dr. Nirala Jacobi, if you have been tested with the 3-hour breath test, and your results may show a true flatline, and you have diarrhea and other SIBO symptoms, then hydrogen sulfide dominant SIBO can be suspected. Sometimes, it is good to follow up with another type of test sugar, such as glucose or fructose.

Patients with hydrogen sulfide SIBO can react to sulfur-containing foods, so following a low-sulfur diet for a few weeks may help manage the symptoms. (Reducing meat, dairy, cruciferous vegetables, onions).
Conventionally the same antibiotic protocol is used (as in the case of methane dominant SIBO) combined with bismuth (11).

What is the best treatment option?

According to a study, herbal treatment can be as effective as Rifaximin. (12) The type of treatment should be evaluated by your practitioner to define the best-customized approach.
Besides using antibiotics and antimicrobials, there is a third type of treatment: the Elemental Diet. It is the only diet that can starve the bacteria with an 80-85% success rate (13).

Summary

If you are experiencing digestive problems and you suspect that SIBO can be the culprit of your symptoms, ask your practitioner to test you for SIBO. Knowing the type of your SIBO can determine the best treatment options.
It is still advisable to dig deeper to find your root causes. Dealing with SIBO requires a holistic approach, supplements/medication, and customized nutrition and lifestyle changes.
I know from my own experience that SIBO can be a super frustrating condition and may require a long journey, but it is possible to get rid of it as I did.

If you would like to get guidance on your SIBO journey, book a free consultation call.

*This post is only for informational purposes; and not meant to diagnose, or treat any disease. I advise consulting with your healthcare practitioner regarding any treatment options or dietary changes.