Small intestinal bacterial overgrowth (SIBO)

SIBO, a small intestinal bacterial overgrowth condition that occurs in the small intestine, indicating an excessive presence of bacteria. It is also referred to as SBBOS, a small bowel bacterial overgrowth. Individuals with SIBO might be only mildly symptomatic suffering from indigestion symptoms or profoundly affected with a malabsorption syndrome.

The SIBO has been recently been associated with an irritable bowel syndrome (IBS) [srs]. It most commonly occurs due to the following

  • reduced stomach acid and its underlying causes
  • Long-standing celiac disease  and a neuropathic motility disorder decrease gut motility and lead to small intestine dysmotility
  • Acute pancreatitis disturbing migrating motor complex (m.m.c.)
  • Usage of strong antibiotics
  • A chronic illness that involves a significant immunosuppression in combined variable immunodeficiency, IgA deficiency, and hypogammaglobulinemia
  • Ileocecal valve (sphincter muscle situated at the junction of the small intestine) dysfunction
  • Chronic alcohol use
  • Copper deficiency


The most common symptoms of SIBO/SBBOS are

  • Bloating and occasional cramping
  • Abdominal fulness
  • Fatigue and weakness
  • Diarrhea/vomiting, and sometimes constipation
  • Fat and protein malabsorption as a result of bacterial deconjugation of bile salts
  • Nutritional deficiencies, especially in fat-soluble vitamins such as (A, D, E, and K)
  • Vitamin B12 deficiency as one of the markers due to competitive uptake of vitamin B12 by bacteria [srs]
  • Impairments in T-cell functions
  • Loss or inability to gain weight and weight gain with mild SIBO
  • Thinning of the mucosa leading to bowel hyper permeability / Leaky gut from toxicity of free bile acids
  • Blunting of the intestinal villi
  • Osteoporosis
  • Implication in Fibromyalgia [srs]
  • Implication in Rosacea [srs]
  • Pale/yellow/fatty stools

Symptoms can also be similar to lactose and fructose intolerances. The overgrowth of bacteria that metabolizes bile salts to insoluble byproducts may lead to fat malabsorption or bile acid diarrhea. Complications can be minimal as vitamin deficiencies, to significant such as fat-soluble vitamin deficiencies leading to Hereditary neuropathies.


At the present time, there is no established procedure to test for the SIBO, however, the most two commonly utilized tests are bacterial stool culture and lactulose or glucose hydrogen breath tests. The gold standard for evaluation of bacterial overgrowth is the aspiration of more than 105 bacteria per millilitre from the small bowel. A healthy small bowel has less than 104 bacteria per millilitre [srs].

Malabsorption can be evaluated by D-xylose test and vitamin levels in the blood.


The treatment would need to address a possible underlying cause while addressing the bacterial overgrowth. In celiac disease patients for example, a strict gluten-free diet will improve the symptoms.

In mainstream medicine, if the outgrowth is significant and/or positively identified, it is usually treated with antibiotics including tetracycline, amoxicillin-clavulanate, neomycin, cephalexin, have been used. However, the most studied antibiotic of action at the present time is rifaximin (narrow-spectrum antibiotic) [srs]. A course of 7-10 days of antibiotics is usually sufficient to treat the condition which may recur if underlying causes are not treated.

In alternative medicine, the following are the treatment options

Commonly, when SIBO is present, the gastric acid production is impaired. Restoring the stomach acid levels can help control bacterial overgrowth. If the SIBO is significant, stimulating gastric acid production may produce moderate bacterial die-off symptoms, therefore it should be done incrementally.

  • Supplements
    • Probiotics containing Bacillus Coagulans and Lactobacillus Reuteri
    • Oregano oil
    • Wild garlic
    • Berberine (found in Oregon grape root)
    • Monolaurin
  • Diet
    • Vegetable based and low fructose diet
    • Include garlic, ginger, turmeric, vinegar, digestive bitters (introduce each one carefully and observe any die-off symptoms)
    • Avoid sugar, honey, apples, peaches, mangoes, watermelon, coconut, fruit juices, dried fruits, pears, wheat
    • Limit raw onions, peanuts and beans
    • An elemental diet taken for two weeks for eliminating SIBO. This deprives the bacteria of a food source while providing nutrition to the body

Pathogen die-off symptoms may include chills, insomnia, brain fog, anxiety and sometimes skin rashes and muscle aches.