Fueling the Gut: Nutrition & Autism

The content in this article is provided for informational purposes only and is not intended as medical advice or as a substitute for the medical advice of a physician. 

Fueling the Gut: How Nutrition Can Help Children with Autism Thrive

Autism is a complex neurodevelopmental disorder that affects individuals in many ways. It is quickly becoming one of the most common developmental disorders in the country. While there is no documented cure for autism, several therapies and interventions can help manage the symptoms and improve quality of life. Nutrition is one intervention that is often overlooked. This article will explore how nutrition can improve autism and the nutrients and foods that can help.

Prevalence refers to the total number of cases of a particular condition in a population at a specific time. According to the Centers for Disease Control and Prevention (CDC), data collected in 2018 show that autism affects an estimated 1 in 44 children in the United States. Just one year earlier, the prevalence was 1 in 54 children. As if that isn’t surprising enough, the prevalence from 2000 to 2021 has increased by 241%. (1) Estimates state that half of all children in the US could be autistic by 2025. (2) While that seems like an aggressive prediction, with statistics like that, we can all agree that this is a growing problem. Now that we’ve discussed the prevalence of autism, let’s look at some of the symptoms commonly associated with this condition.

Autism, or autism spectrum disorder (ASD), is identified by difficulties with social skills, repetitive activities, speech, and nonverbal communication. Autism is a spectrum disorder, meaning that individuals can experience a wide range of symptoms. There are multiple potential causes of autism. It is frequently associated with sensory sensitivities, physical conditions including gut diseases, seizures, or sleep disorders, and psychological difficulties like anxiety, depression, and attention deficits. (3) Let’s break down these symptoms a little further. 

Social Interaction Difficulties (4)
Children with autism experience social challenges, including difficulty understanding, recognizing, and expressing emotions in themselves and others. For example, they may not notice when others are hurt or upset and may not sing or dance as other children will. They also may feel overwhelmed in social circumstances and have difficulty gauging personal space.

Communication Difficulties (4)
Both verbal and nonverbal communication can be challenging for children with autism. An estimated 40% of people with autism are nonverbal. 5 Other challenges with verbal communication can include repeating words or phrases over and over, reversing pronouns,
giving unrelated answers to questions, or using an inappropriate tone of voice. 6 Challenges with nonverbal communication can include improper use of gestures, avoidance of eye contact, and not showing facial expressions.

Repetitive Behaviors (4)
Repetitive behaviors can include repeated movements or actions, sticking to a strict routine, and intense focus on specific topics or objects. These behaviors can provide comfort or security for individuals with autism and interfere with daily activities or social interactions. 

Sensory Issues (4)
Sensory issues are common in individuals with autism. This means they might be extra sensitive to sounds, light, touch, taste, or smell. On the other hand, they may not be sensitive enough to things like pain or temperature. These sensory issues can be overwhelming or distracting, making it hard for individuals to focus or feel comfortable. 

In addition to the communication, social interaction, sensory, and behavioral issues discussed above, multiple chronic conditions are commonly associated with autism. These include feeding issues, disrupted sleep, anxiety, depression, and gastrointestinal (GI) problems. (7) Although these conditions may seem unrelated to autism, recent research suggests that there may be a link…the microbiome. The gut-brain axis is a complex, two-way communication system between the gut and the central nervous system. It connects the brain’s mental and emotional regions to the digestive processes of the gut. A damaged GI system can send signals to the brain, just as a troubled brain can send signals to the gut.

The gut microbiome, a collection of trillions of microorganisms that reside in the GI tract, plays a critical role in the gut-brain axis. The gut microbiome communicates with the central nervous system through multiple pathways, including the immune system, the vagus nerve, and by the production of neurotransmitters. 

Research has shown that the gut microbiome can affect behavior, mood, and cognition. For example, studies have found that changing the gut microbiome through dietary interventions can improve symptoms of depression and anxiety. Similarly, changes in the gut microbiome are associated with various neuropsychiatric disorders, including autism. (8) So let’s discuss specific nutritional changes that can strengthen the microbiome and improve autism. 

Avoid glyphosate
Glyphosate, also known as RoundUp, is an herbicide farmers use to manage and control weeds and maximize crop yield. It is the most widely used herbicide in the United States and the application rates have increased over the past few decades. The increased use has led to higher glyphosate residues within food which have multiple adverse health effects. 

  • First, exposure to glyphosate changes the amount and types of organisms that make up your microbiome. Beneficial bacteria that play essential roles in communication within the gut-brain axis can be severely reduced or eliminated. Alterations like this are associated with neurologic conditions such as autism spectrum disorders, depression, anxiety, Alzheimer’s disease, and Parkinson’s disease. 
  • Secondly, the breakdown of glyphosate by certain organisms in the microbiome leads to another chemical with similar toxicity to glyphosate. The metabolism of glyphosate and the production of this metabolite promotes inflammation the human nervous system. 
  • Lastly, in a healthy microbiome, bacteria produce short-chain fatty acids (SCFA), essential for creating neurotransmitters, including serotonin. Serotonin is crucial for bowel function, gut health, and mood. Changes in the microbiome’s makeup can reduce serotonin production. (9)  

Unfortunately, with the increased use of glyphosate, many more foods contain it. It can be overwhelming and difficult to avoid or eliminate all foods containing glyphosate. In addition, it may be too expensive to purchase the organic forms of all these food items. 

Here’s a tip to consider: Refer to the Environmental Working Group’s (EWG) Dirty Dozen list https://www.ewg.org/foodnews/dirty-dozen.php. These are the top twelve foods with the most pesticide residue and ones that would be best purchased organically. On the other hand, the EWG’s Clean 15 list https://www.ewg.org/foodnews/clean-fifteen.php are foods with little to no pesticide residue that may be safer to buy in their conventional form. (10 ) 

Remove gluten and casein
Gluten is a protein in wheat, rye, barley, oats, and other ingredients that include these grains. Gluten has been linked to leaky gut syndrome and a “leaky” blood-brain barrier. Children with autism have a higher incidence of leaky gut and leaky brain, according to research. (11) Casein is the
main protein found in cow’s milk. Many autistic children lack the enzymes to break down casein in their gut. It is common for gluten-free diets to be combined with casein-free diets in those with autism. 

The connection between using a gluten-free, casein-free diet and autism is based on the assumption that gluten and casein are associated with higher immune responses or autoimmunity. These immune responses result in inflammation, causing leaky gut, which allows for increased absorption of gluten, casein, and their metabolites into the bloodstream and potentially across a leaky blood-brain barrier. These molecules may interact with a child’s brain, negatively affecting their mood and worsening behavioral symptoms. Casein is also rich in glutamate, an excitatory neurotransmitter, which can increase anxiety. (12)

Increase sulforaphane
Sulforaphane is a compound formed almost exclusively in cruciferous vegetables, including broccoli, cauliflower, brussels sprouts, and cabbage. Its beneficial effect on autism might be due to its ability to pass through the blood-brain barrier and protect the brain. It activates genes that
protect cells against oxidative stress, inflammation, and DNA damage, all of which are characteristics of ASD. (13)

Be aware of potential nutrient deficiencies
Children with autism can have unusual eating habits, including aversion or attraction to specific smells, tastes, and textures, leading to a limited diet. In addition, chronic gut issues can lead to reduced nutrient absorption and decreased utilization of nutrients. Some of the nutrients of particular concern are fiber, vitamin D, folate, B vitamins, zinc, and magnesium. 14 Expanding the diet and incorporating foods that contain these nutrients is beneficial. However, supplements may be necessary in some cases. It is important to work closely with a healthcare professional in these situations. 
In conclusion, autism is quickly becoming one of the most common developmental disorders in the country. April is Autism Awareness Month, which aims to increase understanding and acceptance of people with autism. Although awareness, education, compassion, and acceptance are imperative, let’s move from a place of awareness to action. Optimizing nutrition can help to reduce symptoms and improve quality of life. Let’s reduce the increasing trend of autism, give our children the best chance to reach their full potential, grow into healthy adults, and support a vibrant world.


1.) Centers for Disease Control and Prevention. (2022, March 2). Data & statistics on autism spectrum disorder. Centers for Disease Control and Prevention. Retrieved March 4, 2023, from https://www.cdc.gov/ncbddd/autism/data.html
2.) Half of all children will be autistic by 2025, warns senior research scientist at MIT – Alliance for Natural Health USA – Protecting Natural Health. Alliance for Natural Health USA – Protecting Natural Health – ANH Protects Free Speech About Natural Health Modalities,
Bioidentical Hormone Replacement Therapy, Homeopathy and Access To Natural Therapies. (2022, April 1). Retrieved March 4, 2023, from https://anh-usa.org/half-of-all-children-will-be-autistic-by-2025-warns-senior-research-scientist-at-mit/
3.) What is autism? Autism Speaks. (n.d.). Retrieved March 4, 2023, from https://www.autismspeaks.org/what-autism
4.) What are the symptoms of autism? Autism Speaks. (n.d.). Retrieved March 4, 2023, from https://www.autismspeaks.org/what-are-symptoms-autism
5.) Autism statistics and facts. Autism Speaks. (n.d.). Retrieved March 4, 2023, from https://www.autismspeaks.org/autism-statistics asd#:~:text=An%20estimated%2040%20percent%20of, (IQ%2071%E2%80%9385).
6.) Signs of autism. National Autism Association. (n.d.). Retrieved March 4, 2023, from https://nationalautismassociation.org/resources/signs-of-autism/
7.) Medical conditions associated with autism. Autism Speaks. (n.d.). Retrieved March 4, 2023, from https://www.autismspeaks.org/medical-conditions-associated-autism
8.) Grace, T., & Pulikkan, J. (2023, February 28). Explained: How does the gut microbiome link to autism spectrum disorders? The Hindu. Retrieved March 4, 2023, from https://www.thehindu.com/sci-tech/science/explained-how-does-the-gut-microbiome-link-to-
autism-spectrum-disorders/article66528560.ece
9.) Barnett, J. A., Bandy, M. L., & Gibson, D. L. (2022). Is the Use of Glyphosate in Modern Agriculture Resulting in Increased Neuropsychiatric Conditions Through Modulation of the Gut-brain-microbiome Axis?. Frontiers in nutrition, 9, 827384. https://doi.org/10.3389/fnut.2022.827384
10.) EWG’s 2023 Shopper’s Guide to Pesticides in produce. (n.d.). Retrieved March 18, 2023, from https://www.ewg.org/foodnews/
11.) Fiorentino, M., Sapone, A., Senger, S., Camhi, S. S., Kadzielski, S. M., Buie, T. M., Kelly, D. L., Cascella, N., & Fasano, A. (2016). Blood-brain barrier and intestinal epithelial barrier alterations in autism spectrum disorders. Molecular autism, 7, 49. https://doi.org/10.1186/s13229-016-0110-z
12.) Gluten-free casein-free diet. Mindd Foundation. (n.d.). Retrieved March 4, 2023, from https://mindd.org/diet/gluten-free-casein-free-diet/
13.) Singh, K., Connors, S. L., Macklin, E. A., & Zimmerman, A. W. (2014, October 13). Sulforaphane treatment of autism spectrum disorder (ASD). PNAS. Retrieved March 5, 2023, from https://www.pnas.org/doi/10.1073/pnas.1416940111
14.) Nikogosian, A. (2019, May 3). Nutritional deficiencies in kids with autism. Nutritional Deficiencies in Kids with Autism. Retrieved March 4, 2023, from http://southwestfunctionalmedicine.com/nutritional-deficiencies-in-kids-with-autism/

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