SIBO Testing

Small Intestinal Bacterial Overgrowth (SIBO) is a condition where there is an abnormal increase in bacteria within the small intestine. The small intestine typically has fewer bacteria compared to the large intestine, but in cases of SIBO, bacteria from the large intestine may migrate and grow excessively in the small intestine. This overgrowth can disrupt digestion, as these bacteria consume nutrients from food and produce gases, leading to symptoms and nutrient deficiencies

People with SIBO may experience a variety of symptoms, which often resemble other gastrointestinal issues:

• Abdominal bloating and discomfort

• Gas and flatulence

• Diarrhea or constipation

• Abdominal pain or cramping

• Nausea

• Weight loss or, in some cases, weight gain due to malabsorption

• Fatigue and weakness

• Nutrient deficiencies, particularly of Vitamin B12 and fat-soluble vitamins

• Skin rashes or acne, particularly in cases of nutrient malabsorption

• “Brain fog” or difficulty concentrating 

• Intestinal motility disorders

• Chronic pancreatitis

• Abdominal structural/anatomic issues

• Gastroenteritis

• Immunocompromise

• Decreased bacteriostatic digestive secretions (HCl, pancreatic enzymes, bile acids) such as with PPI use

• Ileocecal valve dysfunction

If left untreated, SIBO can lead to complications such as malabsorption and intestinal permeability, or leaky gut.4

Testing for SIBO is recommended if an individual exhibits specific symptoms or has certain conditions that increase their risk:

• Persistent or chronic gastrointestinal symptoms (bloating, gas, diarrhea, constipation)

• Diagnosed with irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD)

• Conditions that affect gut motility, such as diabetes, hypothyroidism, or scleroderma

• History of abdominal surgery, which could impact motility (e.g., removal of part of the intestine)

• Diagnosed malabsorption conditions or unexplained nutrient deficiencies

• Patients with liver disease, chronic pancreatitis, or cirrhosis

• Individuals experiencing systemic symptoms like chronic fatigue, fibromyalgia, or anemia, which may be linked to gut health issues 

A SIBO test, often conducted via a breath test, can yield several outcomes:

• Positive for Hydrogen: Indicates bacterial overgrowth causing excess hydrogen, often linked to diarrhea.

• Positive for Methane: Shows methane-producing bacteria, usually associated with constipation.

• Positive for Both: Suggests mixed overgrowth, with symptoms that might alternate or fluctuate.

• Negative: No bacterial overgrowth detected, suggesting other underlying causes may need to be explored 

Functional medicine providers often take a holistic approach to treating SIBO, focusing on eliminating bacterial overgrowth and improving overall gut health. Common treatments include:

• Antibiotic Therapy: Medications like rifaximin are frequently prescribed to reduce bacterial load. In cases of methane-dominant SIBO, other antibiotics, like neomycin, may be added.

• Dietary Modifications: Patients may be placed on a low-FODMAP diet, which limits foods that can ferment and feed bacteria in the small intestine. An elemental diet may also be used in persistent cases.

• Probiotics and Prebiotics: These may help restore a healthy balance of gut flora, though they are chosen carefully to avoid exacerbating symptoms.

• Herbal Remedies: Herbal antimicrobials, such as oregano oil or berberine, are sometimes used as alternatives to antibiotics, especially for individuals looking for non-pharmaceutical options.

• Nutritional Support: Supplementation with vitamins and minerals is crucial, especially when deficiencies are present due to malabsorption.

• Prokinetic Agents: These medications improve intestinal motility, reducing the risk of bacterial stasis and recurrence

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