SIBO (small intestinal bacterial overgrowth) and SIFO (small intestinal fungal overgrowth) are both serious conditions affecting the small intestine. To understand these conditions and how to treat them, we must first understand the basics of the digestive system.
The Basics of Our Digestive System
Our digestive system starts with our mouth. Once we chew and swallow food it moves through the esophagus which leads the food to the stomach. From there the stomach’s contents move through the small intestine, which is divided into three parts, and then onward to the large intestine or colon. The final step is excretion.
In a normal, healthy digestive system there are more bacteria in the large intestine than in the small intestine. At the junction of the small and large intestine there’s a valve that prevents the backflow of that bacteria from the large intestine back into the small intestine. However, sometimes material does backflow through this junction and the small intestine becomes colonized – or infected – with bacteria that shouldn’t be there. This can lead to SIBO or SIFO.
Symptoms of SIBO or SIFO
Some of the most common symptoms of SIBO and SIFO are:
- Bloating
- Diarrhea
- Constipation
- Sensitivity to foods
- Skin rashes
- Autoimmune conditions
Additionally, individuals with SIBO or SIFO may have high levels of propionic acid, which can be tested via urine Organic Acid Testing (OAT). This is a byproduct of the bacteria that are the cause of SIBO and SIFO. While propionic acid is high in anyone with SIBO, up to 80% of autistic kids have high levels of this propionic acid. Which begs the question: “Is SIBO related to autism in any way?” The numbers indicate a high probability of a connection.
Testing for SIBO and SIFO
There are three simple ways to test for SIBO and SIFO and all of them are non-invasive and can be done at home.
- Breath test: This test can be done at home. However, in my experience, I’ve found it can be hard for kids to follow the pretest instructions and they often have difficulty blowing into the apparatus appropriately.
- Organic Acid Test (OAT): OAT testing is a good alternative to the breath test if your child is having trouble completing it. This test is also helpful for many other issues and can reveal a lot about what’s going on in your child’s gut.
- Stool test: Whether your child is potty trained or incontinent this collecting a stool sample is easy and reveals plenty of helpful information about your child’s gut health.
Treating SIBO and SIFO
3 easy things you can do at home without the help of a physician or specialist to treat your child’s SIBO or SIFO.
- Inulin: This is a prebiotic fiber which feeds the good bugs in the intestine. Inulin reduces propionic acid.
- Omega-3 fatty acids (fish oils): These fatty acids can have an antiinflammatory effect which can help heal the gut.
- Olive oil: Olive oil is high in omega-9 fatty acids. Omega-9 fatty acids can help contribute to the balance of omega’s in your child’s body. When using olive oil to treat SIBO or SIFO remember that it’s not a good idea to cook it at high temperatures. Instead, drizzle it over vegetables or in soup.
Check out my Fullscript list to see my recommendations for SIBO and SIFO healing supplements.
Diet is also important in the treatment of SIBO and SIFO. You should limit the sugar and carb content of your child’s diet. Focus instead on using protein and produce to get your child the healthy fats they need.

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I hope this information has been helpful to you as part of creating Your Autism Game Plan.
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