SIBO Testing and Treatment

This is post three in a series about SIBO. Read post two or start at the beginning.

SIBO test, SIBO treat, functional medicine, Dr. Laura Paris, Monterey, acupuncture

Testing for SIBO

The gold-standard test is a breath test. A gastroenterologist can perform this test in-office, or you can order a breath test kit to test at home. You may find the home kit more comfortable. Or, you may prefer doing it at a doctor’s office.

Before the breath test, you do a prep diet for one day. This consists of food that is not fermented by small intestine gut bacteria. This includes meat, fish, eggs, fat, and broth. It can also include white bread and white rice, which quickly break down into glucose for absorption. It’s a pain, but it is just one day! I prefer that my patients avoid white bread and rice, and just eat protein and fat.

On the morning of the test, you take a breath sample. Then you drink a lactulose (or glucose) solution and take breath samples every 15-20 minutes over the course of two-three hours. Lactulose is highly fermentable, and as it travels through your small intestine, hungry bacteria quickly ferment it. They produce gases that show up in your breath samples. The gases reveal the type of bacteria, the overall load, and where the overgrowth is taking place in your small intestine.

A positive SIBO breath test

A positive test means too many bacteria that produce hydrogen, methane, or hydrogen sulfide gas – or a combination. Hydrogen gas typically indicates bacteria that cause diarrhea. Methane gas producers are actually a slightly different organism called archaea. They are similar to bacteria but not technically classified as bacteria. High levels of methane gas typically cause constipation. Hydrogen sulfide producers usually cause odorous gas.

It is important to know what type of bacteria and how high the gases measure because this will determine specific treatment choices and duration.

SIBO treatment

Treatment is multi-faceted and very much depends on the individual. We functional doctors prefer to have a stool analysis of your digestive function and large intestine microbiota, such as the GI Map test, to create an effective plan for you.

Knocking down the bacteria

In most cases, it is useful to use pharmaceutical antibiotics or antimicrobial herbs to knock down (kill) the bacteria. Antibiotic and herbal combinations vary according to the type of bacteria you have. Research shows that drugs and herbs are equally effective, and in part, it depends on what you best tolerate, in addition to what you have access to.

The gold-standard antibiotic is Xifaxin. At the time of this writing, this medication is expensive, and often difficult to get insurance companies to cover. Some find it easier to order it from overseas, with some sources being superior to others. Xifaxin is a “smart” drug because it specifically acts in your small intestine, without knocking down beneficial bacteria in your large intestine. Also, it does not get absorbed into your bloodstream and go through your liver. Methane-producing archaea require an additional antibiotic called Neomycin.

In the U.S. these antibiotics are often prescribed for 10 days, however research shows they are far more effective if taken for 30 days.

Botanical (herbal) SIBO treatment is often better tolerated. These herbs have powerful broad-spectrum antimicrobial properties. We choose botanical combinations based on your:

  1. Type of gas.
  2. Level of gas.
  3. Constitution and overall health.
  4. Presence of coexisting gut infections (bacteria, yeast, parasites) that show up on a functional stool test such as the GI Map.
  5. Levels of beneficial bacteria.

Dissolving biofilms

Bacteria and yeast create sticky gluey biofilms for protection. Think of biofilms as a web that bacteria hide in. Breaking down these biofilms with specific enzymes allows the antimicrobial (kill) approach to work. You need to take these between meals, so the enzymes work to digest biofilms rather than your food. A supplement called NAC also works well for breaking down biofilms.

Drawing out the bacteria for killing

An adjunctive approach in SIBO treatment is to feed the bacteria, to draw it out in order to kill it. There is evidence this works. We can do this with prebiotic supplements or foods. Some practitioners recommend a low fermentable diet during treatment, such as a low FODMAP approach, however, it can be more effective to draw the bacteria out during treatment by eating FODMAP foods.

Addition of probiotics

There is no research at this time that probiotics improve treatment efficacy. However, if SIBO comes with an imbalance in your colon microbiota (dysbiosis), the idea of rebalancing these populations is logical. Dysbiosis is often part of a SIBO picture, and the resulting inflammation can cause a weakening of the valve between your small and large intestine (ileocecal valve), thus allowing colon bacteria to backwash up into your small intestine.

Dumping in a bunch of random probiotics is not the fix, as SIBO is by definition an environment of too many bacteria. Many a time I’ve pulled patients off their probiotics when there is simply too much bacteria in their small intestines. Also, most probiotic supplements and foods contain lactobacillus strains that produce histamine, which is a problem for many people with SIBO. Probiotics that colonize in your large intestine, with rebalancing properties, are better tolerated. Rebalancing means they have the ability to reduce overgrowths and feed beneficial strains. Some of my favorite SIBO-friendly probiotics include:

  • Megasporebiotic, a soil-based organism with excellent rebalancing properties.
  • Bifidus only as in Therbiotic Factor 4.
  • Lactobacillus Plantarum, especially with methane-producing SIBO.
  • Saccharomyces Boulardi (except for those with colitis or Crohn’s).

Fixing the root cause

Many people relapse after SIBO treatment, especially if they don’t identify the root cause or follow up with a prevention plan. For example, I see lots of folks who took an antibiotic, felt better, and immediately relapsed. This isn’t the way out and can be very frustrating.

The next post in this series is about preventing relapse. I dive into a root-cause approach to preventing SIBO relapse, which is crucial in a SIBO treatment plan.

Please join the converstation with your comments below!

paris healing arts, doctor laura paris, dr. laura paris, dr laura paris

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    1. You’re very welcome! I agree about the Functional Medicine approach to IBS and SIBO being the best choice (currently). Thanks for stopping by!


  1. Could you explain and give examples of the best types of probiotics that grow in the large intestines and have anti-microbial properties? I have been treating SIBO for 9 months using both antibiotics, herbal antibiotics, probiotics, motility agent and low FODMAP diet. My methane dominant SIBO has improved, but I am still positive for hydrogen. In my next treatment I am adding to my arsenal by using a different set of herbal antibiotics, adding a biofilm disruptor, digestive enzymes and supplements like glutamine, and Zinc . After the herbal antibiotics I will take probiotics. Based on your comment about probiotics, I may need to make adjustments there too. Previously, I have used Floramyces by Designs for Health and LactoPrime Plus by Klaire Labs. Maybe I am helping the bacteria recolonize again in the small intestines with these probiotics. I am working with an Integrative Dr., but “ it takes a village” and your insight is appreciated, as well as the information you have already provided.

    Best Regards,

    1. Lori I appreciate you stopping by and also the hard work you’re doing for your health! The longer we all treat SIBO, the more we learn. Your questions are great, but too complex to answer without plunging into your case and your labs. Ask your practitioner, as I assume you have both worked on the root cause of your SIBO (it’s a symptom rather than a diagnosis), and done analysis of the microbes in your large intestine, and know which strains to try to plant there – if any. The more prebiotic food you can tolerate for the rest of your life, the better!

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