Small Intestinal Bacterial Overgrowth (SIBO) is a common condition in which an overgrowth of bacteria occurs in the small intestine leading to IBS symptoms such as gas, bloating, diarrhea or constipation.
In this previous blog pot, I discussed how we test for SIBO. As of late 2020, we are now able to test for three gases: hydrogen (H2), methane (CH4) and hydrogen sulfide (H2S).
There are three effective ways to treat SIBO and I will outline the pros & cons of each approach from my experience. We use all three treatments at our office, assessing which is most appropriate on a case-by-case basis.
ANTIBIOTICS
The primary antibiotic used in treating SIBO is Xifaxan (Rifaximin). Xifaxan is primarily used for hydrogen-positive SIBO with diarrhea or loose stool as a main symptom.
In cases of methane-positive SIBO, in which constipation or slow transit time presents, Xifaxan is usually combined with another antibiotic, such as Neomycin or Metronidazole.
A standard antibiotic course for SIBO is two weeks.
PROS:
- Xifaxan is generally very well tolerated and is not systemically absorbed; its antibiotic actions are fairly localized to the intestines producing less antibiotic side effects
- Xifaxan has anti-inflammatory action on the intestinal mucosa
- Shorter treatment duration compared to herbal antimicrobials; similar to the elemental diet treatment duration
- 70-85% success rate in normalizing the lactulose breath test
CONS:
- Xifaxan is often not covered by insurance and can cost about $1,000+ for a 2-week course
- When Neomycin or Metronidazole are added (in Methane-positive cases) individuals may experience more antibiotic side effects
- Multiple two-week courses are sometimes required
- Many of our clients prefer a more natural approach
HERBAL ANTIMICROBIALS
Antimicrobial herbs are another option for treating SIBO. Both single antimicrobials and broad-spectrum antimicrobial combinations have both been studied and used successfully.
Common herbs used in SIBO treatment include: oil of oregano, allicin, berberine and neem. Many broad-spectrum antimicrobial combinations have been extensively studied as well. We choose the best herbal antimicrobial (or herbal combination) based on the results of breath testing and the individual’s presentation of symptoms.
A typical herbal antimicrobial protocol is four to eight weeks.
PROS:
- Herbal treatments will also address large bowel bacterial imbalances (in addition to SIBO) and can be more comprehensive in that regard
- Some herbal treatments are very well-studied and some studies have demonstrated a success rate that is comparable to, or better than, antibiotics
CONS:
- “Die-off” symptoms may be more significant because antimicrobial herbs target both the small and large bowel
- Longer treatment time, compared to both antibiotics and an elemental diet
- A restricted diet is often recommended alongside the use of herbal antimicrobials
ELEMENTAL DIET
A liquid diet consisting of easily absorbed powdered nutrients that you drink to starve the bacterial overgrowth while still nourishing the body.
An elemental diet program for SIBO is generally two to three weeks.
PROS:
- The most effective SIBO treatment (80% – 85% success rate for 2 – 3 weeks, respectively)
- Shorter treatment duration compared to herbal antimicrobials; similar to the antibiotic treatment duration
- Best treatment choice for reducing very high gas levels, which otherwise may require multiple rounds of antibiotics or herbal antimicrobials
- More broad-spectrum anti-bacterial action than antibiotics and herbal antimicrobials
- Benefits many other conditions besides SIBO such as Inflammatory Bowel Disease, Rheumatoid Arthritis, Cystic Fibrosis and Eosinophilic Esophagitis
- Very well tolerated; some people get almost immediate symptom relief
- May provide a welcomed break from cooking and deciding what to eat
CONS:
- Typically costs $400-$800+ for two-weeks; the cost is determined based on a calculation of your age, height, weight and activity level. (Remember, however, that there are zero food costs during this time and most people pay several hundred dollars for food with their normal two-week diet.)
- No solid food is allowed during this two-week period, which can be psychologically difficult for some
- Occasionally people do not enjoy the taste of the shakes
- Many people who attempt an ED on their own, without proper guidance, do not succeed

I have written extensively about an elemental diet and, at the time of this writing, I have taken nearly 50 people through a step-by-step individualized elemental diet program over the past few years!
See the following posts on an Elemental Diet:
WHAT COMES AFTER SIBO TREATMENT?
After following any of the above treatment options, ideally, we would want to repeat a breath test for SIBO to ensure the bacterial overgrown was fully eradicated.
All successful SIBO treatment plans should then be followed by preventative measures that encourage GI motility and support overall digestive health.