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Small intestine bacterial overgrowth (SIBO) occurs when a growth of bacteria overwhelms the small intestine which should only house small numbers of bacteria.

Research suggests that up to 22% of the population may suffer from SIBO. (Salem & Roland, 2014)

The bottom of this page contains product recommendations to address SIBO symptoms. First, let’s learn the science behind SIBO and probiotics, so you understand which product to choose.

How Does SIBO Develop?

Our understanding of SIBO is still developing as more research is conducted. Initially, it was thought to be rare. Now, it is evident that this condition is not rare. SIBO symptoms range from mild to chronic. (Dukowicz, Lacy, & Levine, 2007)

SIBO develops when more than 104 bacterial organisms per ml are present in the fluid of the small intestine. It does not matter if the bacteria is beneficial or harmful. These bacteria cause health issues because they don’t belong in the small intestine. (Quigley & Quera, 2006)

Numerous factors have been shown to increase someone’s chances of developing SIBO, including:

  • Diminished stomach acid, bile, or pancreatic enzyme output
  • Impaired gastrointestinal motility
  • Use of certain medications including PPIs (antacids)

(Dukowicz, Lacy, & Levine, 2007)

Other risk factors include:

  • Intestinal Neuropathy — When the nerves or muscles in the gut are damaged, food residue isn't moved through effectively and allows for greater fermentation by bacteria
  • Obstructions within the gut — Scarring from surgeries or gastrointestinal diseases such as Crohn's can affect motility and cause bacteria to build up in the small intestine.
  • The presence of diverticulitis These are inflamed pockets that extend out on the wall of the large intestine and can also occur on the small intestine. They may cause a buildup of bacteria.

Eventually, SIBO may cause damage to the intestinal lining, which creates leaky gut syndrome. It also leads to the development of food allergies, food intolerances, and chronic inflammatory processes. (Bures, Cyrany, Kohoutova, et al., 2010)


SIBO symptoms may be mild or chronic and include:

  • Diarrhea
  • Constipation
  • Alternating diarrhea and constipation
  • Gas
  • Bloating
  • Abdominal pain
  • Belching
  • Flatulence
  • Comorbidities, such as irritable bowel syndrome or inflammatory bowel disease
  • Food intolerances to some carbohydrates (e.g., FODMAPs), gluten, proteins, lactose, or fructose
  • Chronic illness
  • Nutrient malabsorption and deficiencies

The cause of many of these symptoms is the buildup of microorganisms and the metabolic waste they excrete through their lifespan. As this waste is released, it causes an abundance of methane and sulfur-based gases, which are responsible for the bloating, gas, and flatulence experienced by individuals. (Posserud et al., 2007)

Supplements and Their Side Effects

SIBO is not caused by one type of bacteria or specifically, good or bad bacteria species. An overgrowth of good or harmful bacteria can cause SIBO.

This is why scientists and health practitioners once believed that probiotics could be harmful to those suffering from SIBO.

What is better understood now is that probiotics are not the issue — if chosen well. The problem with probiotics is that many contain prebiotics, which can worsen SIBO symptoms if chosen inappropriately.

Unfortunately, many probiotic suppliers add prebiotics to their probiotic supplements. This is an issue for SIBO sufferers unless you choose prebiotics known to help with SIBO, such as partially hydrolyzed guar gum.

Some probiotics contain specific ingredients that can worsen or aggravate SIBO symptoms, including:

  • Maltodextrin
  • Lactose
  • Soy
  • Inulin
  • Pectin
  • Tapioca starch


Diet (such as the low FODMAP diet or the Bi-Phasic Diet) is a key component of reducing SIBO symptoms. However, probiotics can also play a role.

Probiotics are particularly effective at treating dysbiosis, if antibiotics are the cause of the imbalance.

Probiotics can assist with SIBO treatment in many ways:

  • Improving motility
  • Helping the small intestine sweep out bacteria
  • Producing antimicrobials that kill off pathogens (such as bad bacteria species), fungus (such as candida), and viruses
  • Helping to improve gut barrier strength and preventing harmful bacteria from adhering to the GI tract
  • Reduction of methane gas
  • Reducing symptoms such as pain, constipation and bloating

(Hawrelak, 2015)

You should continue taking probiotics even after your SIBO symptoms improve, to prevent relapse which is unfortunately common. (Gaon et al., 2002)

Probiotic Supplements for SIBO

Take probiotics in small dosages, then gradually increase your dosage as you start to feel relief from your symptoms.

If you do not feel any better, it is recommended you choose a different strain of probiotics. Below are species recommended for SIBO symptoms:

When taking probiotics for SIBO, adhere to the following:

  • Avoid taking probiotics that also contain prebiotics. Prebiotics have the potential to worsen SIBO symptoms.
  • Avoid taking probiotics that contain additives. Additives feed bacteria, which can worsen SIBO.
  • Stick with probiotics that work for you. If the ones you have chosen alleviate your symptoms, stay on them.

If you and your healthcare provider decide probiotic supplements are the right course of action for your symptoms, we recommend the following:

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Research Citations

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