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(Woodpath is an education site focused exclusively on gut health. Our articles are researched by clinical nutritionists and contain citations at the end of the page.)

Everyone has an upset stomach or feels bloated from time to time. But if you suffer from consistent and unpredictable bouts of digestive upset — especially diarrhea or gut cramping — there could be an underlying issue with your digestive system.

What is SIBO

SIBO (Small Intestinal Bacterial Overgrowth) occurs when the small intestine is overrun with bacteria that don't belong there.

SIBO can be challenging to diagnose. Symptoms may vary and can change from individual to individual, based on the types of bacteria that have infiltrated the small intestine.

It can also be difficult to treat or completely eradicate SIBO. This is because to treat it, you often have to feed some of those same bacteria causing SIBO. The difference is, you have to feed the bacteria to foster growth where that bacteria belongs (like the large intestine).

In a healthy individual, the small bowel is a relatively sterile area of the body where very few bacteria live. Compare that to the large intestine where beneficial bacteria called probiotics colonize to help us digest many of the foods we eat.

We need good gut bacteria to thrive in the large intestine, but it's when they begin creeping upward into the small bowel that problems with SIBO can arise.

Symptoms

SIBO symptoms can include diarrhea, constipation, abdominal pain, gas, bloating, cramping, and in severe cases, fat malabsorption, unintentional weight loss, fatigue, and nutritional deficiencies.

In some cases, increased inflammation and damage to the gut lining result from this overgrowth, especially in older adults.

This type of damage (leaky gut) can create additional health problems, such as inflammatory bowel disease or autoimmune disease.

The symptoms you experience due to SIBO depends entirely on which types of bacteria have overrun the small intestine and how aggressively the problem is treated. (Andrew 2007)

Causes

Common causes of SIBO include:

  • Low stomach acid: Bacteria in food that would typically be neutralized by gastric acids slips through and colonizes the small intestine.
  • Impaired motility: The movement of the bolus (partially digested food) from the small to the large intestine through the ileocecal valve is sluggish. It sits for too long in the small intestine. When this happens, parts of the bolus begin to putrefy — bacteria begins to grow in the small intestine when it should have already moved through into the large. Motility supplements are specifically designed to address this issue.
  • Physical deformity or other physical problems: A condition like diverticulitis is an example of a physical issue in the intestine itself that could create an environment for SIBO. Gastric bypass surgery is another example. This used to be considered a leading cause of SIBO, but a physical problem in the intestine (whether natural or due to surgery or other intervention) is far less common than SIBO occurrences, so doctors have realized that this criterion is not as vital as previously suspected.

Other risk factors that could make you more susceptible to SIBO include:

  • Diabetes mellitus (typeII diabetes) or other metabolic disorders
  • Scleroderma or other connective tissue disorders
  • Autoimmune diseases (like lupus, Crohn's disease, or celiac disease)
  • Conditions that compromise the immune system in general (such as HIV/AIDS)
  • Prolonged use of proton pump inhibitors, anti-spasmodic IBS medications, or antibiotics

Diagnosis

There are a number of ways doctors can determine whether or not you have SIBO. Unfortunately, there's no fail-proof gold standard test to diagnose the condition. As a result, diagnosis can be a combination of testing and professional medical opinion.

In most cases, a gastrointestinal doctor will observe or take note of your reported symptoms in addition to giving you either a glucose or lactulose breath test. 

With either test, you provide a series of breath samples into specialized take-home equipment after eating a limited diet, followed by fasting, then followed by drinking either a glucose or lactulose solution.

The purpose of the breath tests is to determine whether or not the solution you ingest stimulates bacteria in the small intestine. If it does, your breath will contain either excess hydrogen, methane, or both. The presence of one or both of those elements in your test results can contribute to a SIBO diagnosis.

These tests can generate false positives and false negatives. We recommend working with a professional to help you interpret your results and your symptoms.

Treatment

While a quick search online will reveal many diets that claim to cure SIBO naturally, the only way to completely eradicate the bacteria is to take some form of antibiotic.

Effective treatment options come in both prescription and herbal forms.

The powerful, yet targeted, antibiotic Rifaximin (genericname: xifaxan) has been shown in clinical trials to be extremely effective in treating most occurrences of SIBO. (Grace 2013)

This drug isn't without potential side effects, however. Some patients who take xifaxan report hives, diarrhea, and C. difficile infection, which then have to be treated after the initial course of antibiotics.

For a more natural approach, there are herbal antibiotic options, including Dysbiocide, FC Cidal, Candibactin-AR, or Candibactin-BR.

Keep in mind: with herbal antibiotics, treatment time tends to take a bit longer.

Even though these herbal treatments don't require a prescription, it's important to use them under the guidance of a trained professional.

Should any problems arise, your trained medical professional can help guide you in a different direction.

Dietary Support

Diet can’t cure SIBO on its own. But some diets can help you treat your symptoms.

Bacteria feed on carbohydrates. Limiting carbohydrates — specifically a type called FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols) is an effective way to experience relief.

A low FODMAP diet restricts some foods that would otherwise be considered a healthy contribution to your diet. Vegetables like garlic, onions, cauliflower, and sweet potatoes are all examples of restricted foods on a low-FODMAP diet.

These foods are considered prebiotic foods — foods that feed the good bacteria in your gut and contribute to healthy gut flora. But it’s possible that your symptoms exist due to these same bacteria living in the wrong place (your small intestines). As a result, you might want to restrict them.

The Low-FODMAP diet is not meant to be a long-term solution. FODMAP foods feed the gut flora in the large intestine that helps us digest complex carbohydrates and other foods necessary for health. 

Once you've gone through the antibiotic treatment of your choice, begin reintroducing these foods systematically with the help of your medical practitioner.

Read our complete guide to the SIBO diet here.

Lifestyle Changes

Some studies link SIBO and other digestive issues (such as IBS) to physical and emotional stress. Stress reduces gastric acid production. Since low stomach acid is one of the causes of SIBO, it's widely accepted that stress may be a potential contributor to SIBO symptoms.

If you believe you're suffering from SIBO, take steps to reduce the stressors in your life:

  • Ask for help vs. taking on undue stresses
  • Say no to non-critical requests
  • Find healthy stress-reduction practices such as moderate exercise, meditation, or calling a friend

Once you've treated SIBO with antibiotics and alleviated symptoms with dietary changes, one of the many ways to prevent recurrence is to find stress reduction and stress management practices that work for you.

SIBO or IBS?

SIBO can be difficult to diagnose because it can manifest the symptoms of other digestive disorders. Irritable Bowel Syndrome (IBS), for example, shares some of the same symptoms as SIBO. 

Many doctors only treat IBS symptoms, rather than the root cause, meaning a patient could go a long time treating their symptoms without ever receiving a SIBO diagnosis (or medical advice on how to treat it).

Some researchers question whether or not many IBS patients are actually suffering from SIBO. Previously believed to be the result of psychological factors, gastrointestinal doctors and researchers are now considering more physical root causes of IBS, including SIBO. (Ghosha 2017)

If you and your doctor determine supplements are right for you, we recommend Vitamin Bounty Pro-50 (13 strains, 50 billion CFU).

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Research Citations

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