Publish Date

March 24, 2015

Special diets have become increasingly common and more popular in recent years. Reports from both physicians and patients, many with laboratory tests confirming, say they can be helpful for a variety of diseases including autism, ADHD, multiple sclerosis, auto-immunity, rheumatoid arthritis, bowel conditions, and many more. Three diets in particular appear to help address gut dysbiosis, the overgrowth of microbes such as yeast and bacteria, which can be problematic for many individuals. Research shows that more than 70% of children with an Autism Spectrum Disorder (ASD) report a history of GI complaints.1 “Leaky Gut”, or intestinal permeability, results from larger than normal spaces between the cells of the gut wall. These spaces allow undigested food and toxins to enter the blood stream. When this happens, the immune system can mount an attack against the foreign particles which may result in food sensitivities and/or allergies. When the offending foods are eaten again, the release of antibodies triggers inflammation. This chronic inflammation further exacerbates the cycle by lowering Immunoglobulin A (IgA) levels. Adequate IgA levels are required to protect the intestinal tract from the gut pathogens such as clostridia and yeast. This continuous cycle can increase gut dysbiosis and negatively impact the overall health of your patients. All three of these special diets – SCD, GAPS, and Paleo may help address these issues by reducing the amount of undigested and allergenic foods being consumed and healing both the gut and brain.

Understanding how the SCD, GAPS, and Paleo diets may help the gut and brain, as well as the major differences between the three diets, can help you provide guidance to your patients when addressing food allergies, autoimmunity, and gut dysbiosis. All three diets share the basic foundations of reducing carbohydrates, avoiding grains (including those that are gluten-free) avoiding refined sugar, avoiding packaged/processed foods, focusing on nutrient-dense foods, and emphasizing the importance of eating a variety of vegetables. Each diet also has its own unique elements, and here is how they compare:

SCD – Specific Carbohydrate Diet:

  • This diet was pioneered by Dr. Sidney V. Haas.
  • Patients are encouraged to follow the program in the book Breaking the Vicious Cycle by Elaine Gottschall.
  • Carbohydrates allowed on this diet are classified by their molecular structure.
  • Allowed carbohydrates are monosaccharides and have a single molecule structure that allow them to be easily absorbed by the intestine wall.
  • Disaccharides (double molecules) and polysaccharides (chain molecules) are not allowed.
  • Some dried beans and legumes can be added in after symptoms resolve and in accordance with the soaking and preparing instructions from the book.
  • This diet does allow some dairy (fermented/cultured).
  • Results of a Rush University SCD study show the diet leads to better microbial gut diversity.2
  • This diet focuses on reduction of pathogenic organisms in the gut rather than introducing beneficial bacteria.
  • Website:

GAPS – Gut and Psychology Syndrome Diet:

  • Dr. Natasha Campbell-McBride expanded on the principles of GAPS in her book The Gut and Psychology Syndrome.
  • GAPS is very similar to SCD except for that it adds many probiotic-rich, cultured foods.These foods may help recolonize good bacteria and counteract bad bacteria.
  • This diet has more phases and may be seen as more rigorous than SCD.
  • GAPS emphasizes addressing brain health over gut health, but should certainly assist with both.
  • Website:

Paleo Diet:

  • This diet is based upon the concept that the optimal diet is the one to which we are genetically adapted. It recommends modern, everyday foods that mimic the food groups of our pre-agricultural, hunter-gatherer ancestors
  • Paelo allows some starches that the other diets do not allow.
  • It does not allow dairy products.
  • It does not allow legumes or beans.
  • This diet may be seen as the least restrictive of the three diets.
  • Website:

How to know when to suggest a diet like SCD, GAPS or Paleo for your patients: Have clinical tests like our Organic Acids Test or Microbial Organic Acids Test indicated yeast and/or bacterial overgrowth? Have repeated courses of antibiotics and/or antifungals failed to resolve these often chronic disorders? Have you tried multiple probiotics which have failed to repopulate the gut with good bacteria and yeast? Has IgG food allergy testing shown continued food allergies despite removal of the common allergens like wheat, dairy, and soy? Has your patient developed new or increasing food allergies despite being on an “allergy-friendly” diet? If you answered yes to any of these questions, considering a more specific and restrictive diet beyond GFCF (Gluten Free, Casein Free) could be the next step in healing for your patients.

Diet can be a very effective way to reduce harmful gut pathogens by removing their food supply and decreasing the inflammation they cause. Diligence, dedication, and strict adherence is required from your patients to see the full benefits of these special diets. In cases where antibiotics, antifungals, supplements, and probiotics have not been successful, these diets may help reverse the gut dysbiosis, after which reintegrating various supplements and probiotics may be effective . For newly diagnosed patients, implementing one of these diets may be a good way to begin their healing process quickly and effectively. As Ann Wigmore, health practitioner, nutritionist, and whole foods advocate said, “The food you eat can be either the safest and most powerful form of medicine or the slowest form of poison”.

Clinical References

About the Author

Terri Hirning