I wrote here about SIBO (Small Intestine Bacterial Overgrowth): what it is, how to diagnose and treat it.

The Antibiotic Approach (Rifaximin)

I’m not against antibiotics—they are wonderful when you really need them. I do I try to limit antibiotic prescriptions to cases when they are absolutely necessary, though, since most antibiotics can wreak havoc on your gut flora.

The up side of Rifaximin, the primary antibiotic for SIBO, is that it is not systemically absorbed, but stays within the GI tract. This minimizes its side effects. The bacteria are also in the bacteriostatic rather than the bactericidal category, which means they block the reproduction of the bacteria they target but don’t actually wipe them out. This means less gut flora disturbance, if any—in fact, Rifaximin’s side effect profile is similar to placebo. Neomycin, another antibiotic recommended for some cases of SIBO in which methane-producing bacteria are also present, also remains local to the gut. I never prescribe Neomycin by itself, however—it’s Rifaximin, or Rifaximin plus Neomycin, depending on the type of SIBO present.

Unfortunately, there are two main problems with Rifaximin: first, infections tend to recur, and second, it’s still under patent and therefore very expensive. Insurance companies have a tendency to deny coverage, and many of my patients have to pay out of pocket. (I usually recommend a discount card to make it more affordable, but even then, it’s still a few hundred dollars for a ten day course.)

The Herbal Approach

While I probably have more experience treating SIBO with antibiotics, more and more patients either cannot or choose not to go that route. In my experience, the herbs are also quite effective, though. 

This study makes it official: Herbal treatment for SIBO is just as effective as Rifaximin.

Specific formulations tested in this study include a proprietary blend of berberine and essential oils. I’ve also had good success with Allimax, a very powerful extract of garlic.

Recurrence of SIBO

Regardless of the treatment approach, SIBO tends to recur. In most cases this is due to slower bowel motility—often secondary to hypothyroidism, subclinical or otherwise, or high blood sugar which can set you up for gastroparesis. I’ve even seen some cases in which bioidentical progesterone slows down bowel motility—less common, but something to watch out for.

Because of the high rate of recurrence, in addition to searching for and treating these root causes, if they exist, I nearly always prescribe some form of prokinetic after SIBO treatment. Prokinetics help the gut move the way it’s supposed to, so that the bacteria doesn’t just crawl right back from the colon into the small intestine again after treatment. Prokinetics can include herbal Iberogast, or prescriptions such as low dose erythromycin (LDE). Technically LDE is in the antibiotic category, but at low enough doses, it lacks antibiotic properties and acts as a prokinetic only.