Nemechek Protocol

What Is the Nemechek Protocol?

  • While not quite a diet, the Nemechek Protocol was designed by Dr. Patrick Nemechek, DO for children with autism, developmental disorders, sensory processing disorder, apraxia, and ADHD. The protocol combats inflammation, SIBO, and high propionic acid by supplementing with fish oil, extra virgin olive oil, and the prebiotic, inulin, in addition to lifestyle changes. Dr. Nemechek claims the protocol can repair brain function, reverse bacterial overgrowth, restore white blood cell function, and improve symptoms associated with Autism.

  • Here is a brief synopsis of the reasoning behind the Nemechek Protocol: 

    • It is thought that there is a chemical inflammatory state throughout the body, which negatively affects normal brain development and repair. These chemicals are called pro-inflammatory cytokines.

    • The inflammation is caused by a few factors: leaky gut and small intestinal bacterial overgrowth, an overabundance of omega-6s and a lack of omega-3s in the diet, and lastly, something called microglia priming.

      • Microglia are the immune cells of the brain. Inflammation due to infection or injury can prime or activate the microglia. This priming also causes the release of inflammatory cytokines. 

    • Diet can be used to combat this systemic inflammation.

      • Reducing omega-6 fatty acids from vegetable oils like soy, corn, margarine, shortening, sunflower, and safflower. These oils are fed to conventionally raised animals and farmed fish as well, which contributes to higher omega-6 content in these foods. 

      • Increasing Omega-9 fatty acids from extra virgin olive oil, which are capable of blocking the inflammatory stress from omega-6 fatty acids. 

      • Increasing omega-3 fatty acids, as deficiency is another problem. We need DHA which comes from animal tissue and fish. Omega-3s decrease inflammation.

    • Cumulative brain injury is caused by damage to neurons in the head from very common incidents/injuries (for example, a child falls and bumps their head). With this systemic inflammation, damage is left behind after each injury, and the damage piles up, causing cumulative brain injury.

      • Other sources of brain/neuron injury include emotional trauma, severe infection, and surgery, among others. All of these injuries can get repaired incorrectly due to inflammation. Depending on where the brain is injured, this will determine some of the symptoms we see such as hyperactivity, anxiety, etc.

    • It is thought that children with Autism suffer from cumulative brain injury, delayed neuronal pruning, and the effects of propionic acid caused by SIBO.

The Pillars of the Nemechek Protocol

  1. Inulin and/or Rifaxamin

    • To combat SIBO, a prebiotic fiber called inulin works well for younger children.

    • In older children, pre-teens, teens, and adults, inulin may not be as effective. Instead, Rifaxamin is often prescribed. Rifaxamin is a non-absorbable antibiotic that doesn’t damage the bacteria in the colon and reduces propionic acid.

      • Per Dr. Nemechek: “Once propionic acid levels are reduced in children with Autism, an “awakening” is said to occur. Propionic has a sedative effect and when it is gone, anxious behaviors, irritability, hyperactivity, or sleep issues may increase. After 4-8 weeks, these symptoms will go away and there will be brain recovery.”

  2. Olive Oil - California Olive Oil Council certified

  3. Fish Oil - recommended: Nordic Naturals

Next Steps

Recommended Foods

  • Extra virgin olive oil/day (California Olive Oil Council certified)

  • There is no one particular diet that is recommended with the Nemechek protocol. Instead, steps to reduce systemic inflammation are encouraged, which may include organic grass-fed cattle, wild-caught fish, free-range poultry, fruits, vegetables, and whole grains.

  • Raw foods are encouraged as well as low and slow cooking methods (low temps and longer cooking times). Advanced glycation end products (AGEs) are formed when food is heated. High temps and dry cooking methods lead to more AGEs.

  • Limit carbohydrate intake to less than 100 g/day to stimulate a healthy insulin response and improve blood sugar regulation. This can also reduce SIBO because intestinal bacteria thrive on carbohydrates. This recommendation must be taken with a grain of salt. The carbohydrate needs of a growing child must be considered and given priority. 

Foods to Avoid

  • Avoid cooking with vegetable oils like soy, corn, sunflower, and safflower (high in omega-6s). Avoid foods prepared with these oils and instead focus on oils high in omega-3s and omega-9s. 

  • Avoid foods that may contribute to systemic inflammation, which may include added sugars or sweeteners, processed foods, fast foods, etc.

Lifestyle Changes

  • Exercise and physical activity are encouraged at least 3 times per week.

  • Intermittent fasting is another way to activate cellular repair. This is not recommended for growing children.

Recommended Supplements

  • Extra virgin olive oil (in/on foods up to 5 years old, 1/2 Tbsp for kids 5-10 years, 1 Tbsp for kids 11-18 years, and 2 Tbsp for adults)

  • Fish oil (starting dose of 600 mg of omega 3 fatty acids from fish oil/day (EPA+DHA)

    • 0-6 Months Old: 150 mg daily

    • 7-12 Months Old: 300-450 mg daily

    • 1-5 Years Old: 450-600 mg daily

    • 5-7 Years Old: 600-1000 mg daily

    • 8-10 Years Old: 1000-1500 mg daily

    • 11-14 Years Old: 1500-2000 mg daily

    • 15-18 Years Old: 2000 - 3500 mg daily

    • 18+ Years Old: 3000 mg daily of DHA only

  • Inulin prebiotic fiber sprinkled over any liquid or food (2-4 inulin gummies or 1/8 to 1 teaspoon of powdered inulin daily for an autistic child 2-8 years of age). Cut back on the dose if the child develops bloating or gas. Start small!

    • In small amounts, inulin will only feed the natural bacteria in the small intestine, which undergo fermentation and release acid in the small intestine. The invading bacteria from the colon don’t like acid and they will regress, causing less inflammation, less propionic acid production.  

  • Non-prescription vitamins and supplements should be stopped during this protocol, although prescription medications should be continued.

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.

Nemechek Protocol in the Research

Propionic Acid Induces Autism Symptoms

  • Propionic acid alters behaviors of relevance (social interaction, anxiety-related behaviors, abnormal motor movements, hypoactivity) to ASD in juvenile rats. [1]

  • We propose that patients diagnosed with propionic acidemia should be screened for Autism Spectrum Disorder. [2]

  • Increased level of propionic acid is associated with various neurological pathologies, including autism. [3]

  • Propionic acid induced social impairment, repetitive behavior, hyperlocomotion, anxiety and low exploratory activity in rats. [4]

Microglia Priming and Brain Inflammation

  • Among rats, propionic acid-treated brains revealed reduced neuron number, an increase of the number of glial cells and the activation of astrocytes and microglia. [5]

  • Postnatal propionic acid-treated rats showed higher levels of inflammation in the cerebellum, brainstem and prefrontal cortex. [6]

Gut Inflammation

  • Gut dysbiosis could contribute to the low-grade systemic inflammatory state reported in patients with GI comorbidities. [7]

Probiotics and Prebiotics

  • Pro-and prebiotic supplements may be effective to revive healthy digestive system function in autistic patients. [8]

  • The administration of probiotics (mostly a mixture of Bifidobacteria, Streptococci and Lactobacilli) is the most promising treatment for neurobehavioural symptoms and bowel dysfunction. [9]

Omega 3s

See the omega-3 note for more

  • Impairment of lipid metabolic pathways may contribute to the development of autism; however, supplementation with ω-3 and vitamin B12 can result in a positive therapeutic effect. [10]

  • This case report suggests omega-3 and vitamin D co-supplementation as a potential safe-effective therapeutic strategy to treat core symptoms of ASD. [11]

  • Vitamin D and omega-3s reduced irritability symptoms in children with ASD. [12]

  • DHA may promote neuronal protection in offspring and act as a modifiable risk factor for ASD and ADHD. [13]

  • Supplementation of omega 3 fatty acids may improve hyperactivity, lethargy, and stereotypy in ASD patients. [14]

SIBO

  • SIBO was significantly associated with worse symptoms of autism, demonstrating that children with SIBO may significantly contribute to symptoms of autism. [15]


The Bottom Line

The Nemechek Protocol is straightforward and fairly easy to follow. The diet recommendations are minimal and the supplement recommendations are relatively inexpensive. The most difficult part for families may be minimizing processed foods which are often high in omega 6 fatty acids but this is something that could be done gradually. There will likely be an increased grocery cost due to improving the quality of foods consumed. There are also a plethora of resources to help with the implementation of this protocol. 

Scale: 1 - 5 Stars ★ (5 Stars Being the Best)

We rate the quality and quantity of the Research supporting the efficacy of the diet in improving symptoms as well as the Ease of Adherence, taking into account the cost, resources available, time required, social acclimation to the diet including options available in restaurants and grocery stores which assist in convenience and adherence

Ease of Adherence ★★★★

This diet is one of the most simple to follow because the restrictions are minimal and the supplements are readily accessible for most families.

Research ★★★

There is no direct research on the Nemechek protocol but the research does support, to some extent, the claims and reasoning behind the protocol. 

Grade: B

Disclaimer: The information provided in the Autism Nutrition Library is intended for educational purposes only and should not be interpreted as medical nutrition therapy, nutrition counseling, diagnosis, prognosis, health care treatment, instruction, advice, or any other individualized medical service. Always let your physician know about any of your health concerns, and check with your doctor or dietitian before making any diet, medication, exercise, or lifestyle changes. 

The information provided in the Autism Nutrition Library is intended for educational purposes only and should not be interpreted as medical nutrition therapy, nutrition counseling, diagnosis, prognosis, health care treatment, instruction, advice, or any other individualized medical service. Always let your physician know about any of your health concerns, and check with your doctor or dietitian before making any diet, medication, exercise, or lifestyle changes. 


  • [1] Shams S, Foley KA, Kavaliers M, MacFabe DF, Ossenkopp KP. Systemic treatment with the enteric bacterial metabolic product propionic acid results in reduction of social behavior in juvenile rats: Contribution to a rodent model of autism spectrum disorder. Dev Psychobiol. 2019;61(5):688-99.

    [2] Witters P, Debbold E, Crivelly K, et al. Autism in patients with propionic acidemia. Mol Genet Metab. 2016;119(4):317-21.

    [3] Lobzhanidze G, Lordkipanidze T, Zhvania M, et al. Effect of propionic acid on the morphology of the amygdala in adolescent male rats and their behavior. Micron. 2019;125:102732.

    [4] Mirza R, Sharma B. A selective peroxisome proliferator-activated receptor-γ agonist benefited propionic acid induced autism-like behavioral phenotypes in rats by attenuation of neuroinflammation and oxidative stress. Chem Biol Interact. 2019;311:108758.

    [5] Mirza R, Sharma B. A selective peroxisome proliferator-activated receptor-γ agonist benefited propionic acid induced autism-like behavioral phenotypes in rats by attenuation of neuroinflammation and oxidative stress. Chem Biol Interact. 2019;311:108758.

    [6] Mirza R, Sharma B. A selective peroxisome proliferator-activated receptor-γ agonist benefited propionic acid induced autism-like behavioral phenotypes in rats by attenuation of neuroinflammation and oxidative stress. Chem Biol Interact. 2019;311:108758.

    [7] Fattorusso A, Di Genova L, Dell'Isola GB, Mencaroni E, Esposito S. Autism Spectrum Disorders and the Gut Microbiota. Nutrients. 2019;11(3):E521.

    [8] Aabed K, Shafi Bhat R, Moubayed N, et al. Ameliorative effect of probiotics (Lactobacillus paracaseii and Protexin®) and prebiotics (propolis and bee pollen) on clindamycin and propionic acid-induced oxidative stress and altered gut microbiota in a rodent model of autism. Cell Mol Biol (Noisy-le-grand). 2019;65(1):1-7.

    [9] Fattorusso A, Di Genova L, Dell'Isola GB, Mencaroni E, Esposito S. Autism Spectrum Disorders and the Gut Microbiota. Nutrients. 2019;11(3):E521.

    [10] Alfawaz H, Al-Onazi M, Bukhari SI, et al. The Independent and Combined Effects of Omega-3 and Vitamin B12 in Ameliorating Propionic Acid Induced Biochemical Features in Juvenile Rats as Rodent Model of Autism. J Mol Neurosci. 2018;66(3):403-13.

    [11] Infante M, Sears B, Rizzo AM, et al. Omega-3 PUFAs and vitamin D co-supplementation as a safe-effective therapeutic approach for core symptoms of autism spectrum disorder: case report and literature review. Nutr Neurosci. [published online: December 13, 2018]. 10.1080/1028415X.2018.1557385

    [12] Mazahery H, Conlon CA, Beck KL, et al. A randomised controlled trial of vitamin D and omega-3 long chain polyunsaturated fatty acids in the treatment of irritability and hyperactivity among children with autism spectrum disorder. J Steroid Biochem Mol Biol. 2019;187:9-16.

    [13] Martins BP, Bandarra NM, Figueiredo-Braga M. The role of marine omega-3 in human neurodevelopment, including Autism Spectrum Disorders and Attention-Deficit/Hyperactivity Disorder - a review. Crit Rev Food Sci Nutr. 2020;60(9):1431-46.

    [14] Cheng YS, Tseng PT, Chen YW, et al. Supplementation of omega 3 fatty acids may improve hyperactivity, lethargy, and stereotypy in children with autism spectrum disorders: a meta-analysis of randomized controlled trials. Neuropsychiatr Dis Treat. 2017;13:2531-43.

    [15] 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.AUTHOR

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