Not that long ago, small intestinal bacterial overgrowth (SIBO) was not even on the radar of most healthcare practitioners. Today, most practitioners—and many patients—are well aware of the negative issues that can occur when bacteria take over the small intestines.

What is SIBO?

SIBO can be a complex issue to address. According to Sarah Cook, ND, the author of a research guide on the subject published by the Natural Medicine Journal, SIBO’s “many causes, manifestations, and comorbid conditions make it much more complex than a simple infection. As researchers discover more about the complex interactions between the intestinal microbiome and other body systems, dysbiotic conditions like SIBO become increasingly relevant”. (1)

While researchers continue to crack the code regarding SIBO causes and comorbidities, there are many aspects of this condition that have become crystal clear. This is due mainly to clinical information that can be gleaned from the scientific literature. Let’s take a closer look at what we know for sure when it comes to SIBO.

A doctor examining a patient's stomach

While awareness about SIBO was limited for quite some time, anywhere from 6 to 15 percent of healthy, asymptomatic people have SIBO.

SIBO symptoms and diagnosis

Statistics vary dramatically when it comes to determining just how prevalent SIBO is among the general population. According to a 2016 article written by Dr. Amy Nett, MD, anywhere from 6 to 15 percent of healthy, asymptomatic people have SIBO. Dr. Nett concludes that “SIBO is largely under-diagnosed. This is because many people don’t seek medical care for their SIBO symptoms and because many doctors aren’t aware of how common SIBO is”. (2) Proper diagnosis of SIBO symptoms is the key to identifying the condition in clinical practice.

In addition to thorough health history and evaluation, healthcare professionals are now recognizing that hydrogen/methane breath testing is the best way to diagnose SIBO. According to a 2017 paper published in the American Journal of Gastroenterology, the North American Consensus group had 100% agreement that hydrogen/methane breath testing is an effective diagnostic tool for the diagnosis of SIBO. (3) In addition to breath testing, understanding risk factors is important.

Risk factors for SIBO

  • Structural/anatomical issues such as small intestinal diverticula or strictures, fistulas, or gastric resection
  • Motility disorders such as gastroparesis or celiac
  • Metabolic disorders such as diabetes
  • Organ system issues such as those with the liver, kidneys, or pancreas
  • Malnutrition or immunodeficiency
  • Recurrent use of antibiotics or gastric suppression medications (4)

Did you know?
People with irritable bowel syndrome (IBS) are also at increased risk of SIBO. Some estimates show as high as 80% of people with IBS also have SIBO.

The digestive symptoms associated with SIBO can be the same as IBS, irritable bowel disorder (IBD), and other digestive issues. Once SIBO has been identified, there is no question that diet can play a key role in balancing bacteria in the small intestines.

Diets and foods for SIBO

Because food directly impacts bacterial balance, it makes sense that diet would be a great first place to start when it comes to addressing overgrowth. The focus of any SIBO related dietary recommendation is on reducing the ingestion of fermentable carbohydrates.

FODMAP diet for SIBO

Just as information about SIBO has been emerging over the past decade, so has knowledge of the FODMAP diet. FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. These poorly absorbed, short-chain carbohydrates found in some foods are rapidly fermented and can cause excessive fluid and gas accumulation, bloating, abdominal pain, and distention. Research shows that a FODMAP diet can help patients who have IBS, a SIBO-related condition. (5)

Bowls of beans including lentils, nuts and seeds on top of a cutting board

Food directly impacts bacterial balance and diet can play a key role in addressing overgrowth in the small intestines.

FODMAPs are found in some vegetables and fruits, beans, lentils, wheat, and dairy products that contain lactose. Foods containing high fructose corn syrup and artificial sweeteners are also considered FODMAP foods. When offending FODMAP foods are eliminated from the diet, digestive issues diminish, and bacterial balance is achieved.

Elemental diet for SIBO

Another diet for SIBO actually isn’t really a diet at all. It’s an elemental formulation that the patient takes in place of food for several days or as long as a month. (6) These formulations contain macronutrients fortified with essential vitamins, minerals, amino acids, and electrolytes. These elemental diet formulations should only be consumed under medical supervision.

Dietary supplements for SIBO

In addition to diet, herbal antimicrobials can be considered for patients who do not respond to antibiotics, those who relapse frequently, or patients who simply prefer natural therapies. Many natural therapies have been shown to be effective and are worth considering. In fact, a 2014 trial demonstrated that herbal therapy was just as effective for SIBO compared to the antibiotic rifaximin. (7)

Medical herb called Clove in plant form

When you eliminate offending FODMAP foods from your diet and add herbs such as cloves, digestive issues diminish and bacterial balance is achieved.

A variety of herbs have anecdotal or animal studies demonstrating antimicrobial efficacy. These medical herbs include:

  • Berberine
  • Oregon grape (Mahonia aquifolium)
  • Mugwort (Artemesia vulgaris)
  • Pomegranate (Punica granatum)
  • Oregano (Origanum vulgare)
  • Neem (Azadirachta indica)
  • Enteric-coated peppermint oil (Mentha piperita)
  • Clove (Syzygium aromaticum)

Regarding probiotics and prebiotics, there are a few small clinical trials suggesting that they may help; however, there are also studies showing that probiotics can worsen SIBO. (9) In fact, aggravation from prebiotics or fermented foods is actually considered a key clinical clue that may help diagnose SIBO. (8)

The bottom line

This issue of addressing SIBO in clinical practice has become so important that there is now an annual conference devoted to the subject. SIBO should definitely be on the radar of all healthcare practitioners, especially those who have patients with any functional digestive issues. According to Allison Siebecker, ND, MSOM, LAc, it’s also important to note that about two-thirds of SIBO cases become chronic or relapse, which requires a proactive plan for ongoing management. (10) This can be accomplished through an integrative approach that includes diet and dietary supplements.

Do you have any thoughts to share on SIBO symptoms, treatment, or diet? Comment below!

Fullscript simplifies supplement dispensing.

Create your dispensary today I'm a patient
  1. Cook S. Small intestinal bacterial overgrowth: A clinician’s guide to evaluation and treatment. Natural Medicine Journal. 2017.
  2. Nett A. SIBO—What causes it and why it’s so hard to treat. Kresser Institute. 2016;July 5.
  3. Rezaie A, Buresi M, Lembo A, et al. Hydrogen and Methane-Based Breath Testing in Gastrointestinal Disorders: The North American Consensus. The American Journal of Gastroenterology. 2017;112(5):775-784.
  4. Dukowicz AC, Lacy BE. Small intestinal bacterial overgrowth. Gastroenterology & Hepatology. 2007;3(2):112-122.
  5. Magge S, Lembo A. Low-FODMAP diet for treatment of irritable bowel syndrome. Gastroenterology & Hepatology. 2012;8(11):739-745.
  6. Altman L. The elemental diet for SIBO and other gut conditions: An interview by Tina Kaczor, ND, FABNO. Natural Medicine Journal. 2017;9(9).
  7. Chedid V, Dhalla S, Clarke JO, et al. Herbal therapy is equivalent to rifaximin for the treatment of small intestinal bacterial overgrowth. Global Advances in Health and Medicine. 2014;3(3):16-24.
  8. Khalighi AR, Khalighi MR, Behdani R, et al. Evaluating the efficacy of probiotic on treatment in patients with small intestinal bacterial overgrowth (SIBO)—a pilot study. Indian Journal of Medical Research. 2014;140(5):604-8.
  9. Rao S, Rehman A, Yu S, de Andio N. Brain fogginess, gas and bloating: a link between SIBO, probiotics and metabolic acidosis. Clinical and Translational Gastroenterology. 2018;9(6).
  10. Scarpignato C. Takeaways from the 2017 Integrative SIBO Conference. Natural Medicine Journal. 2017;9(6).