Small Intestine Bacterial Overgrowth
What is SIBO?
SIBO stands for Small Intestine Bacterial Overgrowth, which is an accumulation or overgrowth of bacteria in the small intestine. [1] Typically this comes from an extension of bacteria from the colon into the small intestine. [11]
The bacteria interfere with our normal digestion and absorption processes and are associated with damage to the lining of the small intestine. [1] Larger food particles which aren’t fully digested can then pass through the damaged lining and activate our immune system, causing inflammation and food sensitivities or allergies. [1]
The bacteria consume the food that isn’t absorbed in our small intestine. The bacteria then reproduce quickly, which furthers the problem and they also produce gasses which can cause pain, bloating, constipation or diarrhea. [1]
Some studies suggest that up to 80% of people with IBS may actually have SIBO. [2, 3]
There are three ways to test for SIBO.
Small Bowel Aspirate and Culture
This is when an endoscope is placed down the throat into the small intestine. Fluid is collected and tested for bacteria. [9]
SIBO Breath Test
Breath testing measures the hydrogen and methane gas produced by bacteria in the small intestine that has diffused into the blood, then lungs, and is exhaled. [4] There are two forms of this test, one uses lactulose and the other uses glucose.
This test is available from Genova. We suggest working with a practitioner to order and interpret these panels.
IBS Blood Test
The IBS Blood test measures antibodies against the bacterial toxin Cytolethal Distending Toxin B (CdtB) and the small intestine nerve protein Vinculin. It detects SIBO that developed after bacterial food poisoning through an autoimmune process. [4]
This test is available through Vibrant America and Cyrex Labs. We suggest working with a practitioner to order and interpret these panels.
SIBO is linked to autism because there is some research in which SIBO was significantly associated with worse symptoms of autism, demonstrating that children with SIBO may significantly contribute to symptoms of autism. [5]
Antibiotics like Rifaximin, Metronidazole and Neomycin are typically recommended to combat SIBO. [11, 12]
Signs & Symptoms
SIBO has many signs and symptoms because it can affect so much of the body. Symptoms often resemble IBS but SIBO will respond to antibiotics and IBS will not.[11]
Symptoms of SIBO include [2]:
Gas
Abdominal pain, bloating
Constipation, diarrhea or both
Heartburn or GERD
Nausea
Food sensitivities including histamine intolerance
Headaches
Joint pain
Fatigue
Skin issues like rashes or eczema
Respiratory issues like asthma
Malabsorption of fats resulting in fatty, floating stools and possible deficiencies in fat soluble vitamins A,D,E and K [7]
Deficiencies in iron, thiamin and vitamin B12 [7]
Mood disorders
Weight loss or stunted growth [6]
Contributing Factors
Gastrointestinal infections, including food poisoning, are thought to be a common cause of SIBO (& IBS). [4]
Medications that suppress acid production are also thought to be a cause.
Conditions that affect gastric motility may cause SIBO, things like chronic constipation, encopresis, short bowel syndrome or cystic fibrosis. [6]
Those with IBS, Celiac disease, Crohn’s disease, liver cirrhosis, non-alcoholic fatty liver disease, and scleroderma are also more likely to have SIBO. [10]
Next Steps
Diet
The most appropriate diet for SIBO will vary depending on the person. Recommendations include:
Rebecca Coomes has created a number of cookbooks using the SIBO Bi-phasic Diet approach.
Supplements
Herbal antibiotics are often recommended to combat SIBO. The use of some of these herbal options is not recommended and/or may not be safe for children. Options include:
Allicin from garlic
Berberine
Olive leaf extract
Thyme
Clove
Cinnamon
Wormwood
Pau d’Arco
Practitioners may also recommend herbal blends that contain a combination of the above mentioned herbs. Some examples include:
FC Cidal and Dysbiocide by Biotics Research
Candibactin-AR and Candibactin-BR by Metagenics
The use of probiotics with SIBO is controversial. In some studies, probiotics have been beneficial but in some studies probiotics have worsened SIBO symptoms. [10, 11] We recommend working with a practitioner to determine what bacterial species and dose is appropriate.
Supplements containing ginger can promote optimal motility in the gastrointestinal tract which helps combat SIBO by supporting the migrating motor complex of the GI tract.
Avoid acid suppressing medications like proton pump inhibitors (PPIs) for GERD or heartburn. These medications reduce acid and increase the risk that SIBO will return. Support natural acid production with apple cider vinegar, betaine HCl and/or bitters.
Lifestyle
Dr. Allison Siebecker is an expert on SIBO and provides a wealth of information on her website as well as support for SIBO symptom relief.
DISCLAIMER: Before starting any supplement or medication, always consult with your healthcare provider to ensure it is a good fit for your child. Dosage can vary based on age, weight, gender, and current diet.
SIBO & Autism in the Research
SIBO and Herbal Antibiotics
Herbal therapies are at least as effective as rifaximin for resolution of SIBO by LBT. Herbals also appear to be as effective as triple antibiotic therapy for SIBO rescue therapy for rifaximin non-responders. [8]
SIBO and Abdominal Pain
One study found an association between SIBO and allergic disease, especially allergic rhinitis, cow's milk protein allergy and asthma. Thus, SIBO should be ruled out in pediatric patients with chronic abdominal pain and allergic disease. [13]
SIBO and Probiotics
Probiotics may enhance the effectiveness of antibiotics as demonstrated in a recent study where patients treated with rifaximin along with probiotics (Lactobacillus casei) had greater improvement in their symptoms with dual therapy as opposed to antibiotics alone. [10]
The use of probiotics can potentially increase the risk for methane predominant variant of SIBO which has been associated with constipation-predominant symptoms. [10]
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[1] Overview. SIBO - Small Intestine Bacterial Overgrowth. Accessed August 29, 2022. https://www.siboinfo.com/overview.html
[2] Symptoms. SIBO - Small Intestine Bacterial Overgrowth. Accessed August 29, 2022. https://www.siboinfo.com/symptoms.html
[3] SIBO (small intestinal bacterial overgrowth): Symptoms, diet, causes & what it is. Cleveland Clinic. Accessed August 29, 2022. https://my.clevelandclinic.org/health/diseases/21820-small-intestinal-bacterial-overgrowth-sibo
[4] Testing. SIBO - Small Intestine Bacterial Overgrowth. Accessed August 29, 2022. https://www.siboinfo.com/testing1.html
[5] Wang L, Yu YM, Zhang YQ, Zhang J, Lu N, Liu N. Hydrogen breath test to detect small intestinal bacterial overgrowth: a prevalence case-control study in autism. Eur Child Adolesc Psychiatry. 2018;27(2):233-40.
[6] Avelar Rodriguez D, Ryan PM, Toro Monjaraz EM, Ramirez Mayans JA, Quigley EM. Small Intestinal Bacterial Overgrowth in Children: A State-Of-The-Art Review. Front Pediatr. 2019;7:363.
[7] Ellis E. Small intestinal bacterial overgrowth. Food & Nutrition Magazine. Published December 16, 2021. Accessed August 29, 2022. https://foodandnutrition.org/from-the-magazine/small-intestinal-bacterial-overgrowth/
[8] Chedid V, Dhalla S, Clarke JO, et al. Herbal therapy is equivalent to rifaximin for the treatment of small intestinal bacterial overgrowth. Glob Adv Health Med. 2014;3(3):16-24.
[9] Ren X, Di Z, Zhang Z, et al. Chinese herbal medicine for the treatment of small intestinal bacterial overgrowth (SIBO): A protocol for systematic review and meta-analysis. Medicine (Baltimore). 2020;99(51):e23737.
[10] Achufusi TGO, Sharma A, Zamora EA, Manocha D. Small Intestinal Bacterial Overgrowth: Comprehensive Review of Diagnosis, Prevention, and Treatment Methods. Cureus. 2020;12(6):e8860.
[11] Bures J, Cyrany J, Kohoutova D, et al. Small intestinal bacterial overgrowth syndrome. World J Gastroenterol. 2010;16(24):2978-90.
[12] Treatment. SIBO - Small Intestine Bacterial Overgrowth. Accessed August 31, 2022. https://www.siboinfo.com/treatment.html
[13] Peña-Vélez R, Toro-Monjaraz E, Avelar-Rodríguez D, et al. Small intestinal bacterial overgrowth: could it be associated with chronic abdominal pain in children with allergic diseases. Rev Esp Enferm Dig. 2019;111(12):927-30.
