Gluten- and Dairy-Free Diets Can Be Game-Changing for Children with Autism.

As a parent of a child on the autism spectrum, you've likely come across the idea of

removing gluten and dairy from your child’s diet. But what does the science really say? Is

it just another dietary trend, or is there something more profound going on beneath the

surface?

Let’s unpack the research and biology behind why gluten- and dairy-free (GF/DF) diets

can be so powerful for many children with autism—and how these common foods can

impact the brain, gut, and immune system in ways we’re only just beginning to

understand.

1. The Gut-Brain Connection Is Real

Children on the autism spectrum often present with digestive issues—bloating,

constipation, diarrhoea, and discomfort. This isn’t just coincidence. The gut and brain are

intricately connected through what's called the gut-brain axis (there is more than 40 years' worth of research on this topic). When the gut is inflamed or imbalanced, it can influence mood, behaviour, focus, and more.

2. Leaky Gut and the Role of Zonulin

One key player in this story is zonulin, a protein that regulates the tight junctions in the

intestinal lining. When zonulin levels are elevated, it can cause the intestinal barrier to

become "leaky", allowing partially digested food proteins, bacteria, and toxins to pass

into the bloodstream—an issue known as intestinal permeability.

Research shows that gluten, a component of wheat—can trigger the release of zonulin in

susceptible individuals, especially those with a genetic predisposition. This can be

particularly problematic in children with autism, many of whom have been shown to

exhibit signs of increased intestinal permeability.

➡ Increased gut permeability is associated with systemic inflammation, immune

activation, and behavioural changes.

3. Dairy, Folate Receptor Alpha Autoantibodies & Brain Development

Dairy proteins, particularly casein, can cross-react with a critical protein in the body called the folate receptor alpha (FRα). This receptor is essential for transporting active folate (5-MTHF) into the brain. In some children, the immune system mistakenly identifies FRα as a threat and produces autoantibodies against it. These Folate Receptor Alpha Autoantibodies (FRAAs) can block folate transport across the blood-brain barrier, leading to cerebral folate deficiency—a condition associated with developmental delay, irritability, sleep disturbances, and autistic features.

The theory is that dairy proteins may increase the risk of FRAA production via molecular

mimicry—essentially tricking the immune system into attacking the wrong target.

➡ Removing dairy may reduce immune cross-reactivity and improve folate transport into the brain—supporting mood, cognition, and neurological development. Read my article on folate for a lot more information about this.

4. Opioid-Like Peptides from Gluten and Casein

When gluten and casein are not properly digested, they can form exorphins—opioid-like

peptides such as gliadorphin and casomorphin. These compounds can bind to opioid

receptors in the brain and affect behaviour, mood, and cognitive function.

These exorphins may contribute to:

• Foggy thinking or lack of focus

• Emotional dysregulation

• Repetitive behaviours

• Altered pain sensitivity

By removing gluten and dairy, many parents report significant improvements in these

areas.

5. Gut Fermentation, Dysbiosis, and Behaviour

The gut microbiome is another crucial piece of the puzzle. In children with autism, studies

have often found microbial imbalances—with higher levels of gas-producing bacteria

such as Clostridia and Desulfovibrio.

Gluten and dairy can act as fermentable substrates (especially when maldigested),

feeding these bacteria and increasing the production of toxic metabolites like ammonia,

phenols, and short-chain fatty acids.

These metabolites can:

• Damage the gut lining

• Trigger inflammation

• Disrupt neurotransmitter balance

Reducing gluten and dairy can help shift the microbiome, decrease gut-derived toxins,

and improve overall behaviour and wellbeing.

6. Immune Activation & Food Sensitivities

Children with autism often have immune dysregulation. Chronic exposure to gluten and

dairy can drive low-grade inflammation, especially if there are underlying sensitivities or

intolerances. This inflammation can manifest not just in the gut, but also in the brain,

contributing to what some researchers refer to as neuroinflammation. Food sensitivity testing (IgG) and elimination diets often reveal that gluten and dairy are

among the most reactive foods for these children.

➡ Removing these trigger foods can significantly reduce inflammation and support

clearer thinking, better mood, and calmer behaviour.

7. What the Research and Families Say

A growing number of studies and thousands of parental reports point to the benefits of

GF/DF diets:

• A 2020 systematic review found that gluten- and casein-free diets were associated with

improvements in communication, attention, and social behaviours in children with ASD,

especially those with gastrointestinal symptoms.

• In clinical practice, many practitioners see remarkable changes in children after dietary

intervention—from improved speech to better sleep and increased emotional

regulation.

But Is It for Every Child?

Not every child with autism will respond in the same way. However, children who exhibit

gut issues, immune dysregulation, food sensitivities, or developmental regression usually

benefit significantly. A supervised trial of a GF/DF diet, guided by a knowledgeable

practitioner, is a safe and evidence-informed step to seriously consider, and is often the

first big step towards healing.

Getting Started: Tips for Parents

• Read labels carefully: Gluten and casein can hide in many processed foods.

• Choose whole, nutrient-dense alternatives: Think fresh vegetables, fruits, quality

protein, and healthy fats.

• Support digestion: Digestive enzymes and gut healing nutrients like zinc, glutamine,

and probiotics can help. Check in with a practitioner to help you with this.

• Track changes: Keep a food and behaviour diary—you might be amazed at what you

discover.

Final Thoughts

You know your child best. If your instincts tell you something’s off—or if you've tried

everything else—changing their diet can be a powerful piece of the puzzle. Gluten and

dairy may seem like harmless staples, but in sensitive children, they can act like

saboteurs—disrupting the gut, inflaming the brain, and short-circuiting communication

pathways.

Thankfully, when we identify these triggers and give the body what it needs to thrive,

profound healing is possible. Gluten and dairy free in autism might be the easiest thing to make a big difference.

Amanda Downsborough, BSc, PGDip, GCert, MSc, ACAAM,

Functional & Nutrigenomic Medicine Practitioner

Brain Kids – www.brainkids.com.au

About the Author

Amanda Downsborough, BSc, PGDip, GCert, MSc, ACAAM, is a Functional and Nutrigenomic Medicine Practitioner specialising in autism and child neurodevelopment. Through her practice, Brain Kids, Amanda combines functional medicine, genetics, and neuroscience to uncover the biochemical and environmental factors affecting children’s health. Her work empowers families with science-based strategies to support brain balance, behaviour, and lifelong wellbeing.

Disclaimer

This information is provided for educational purposes only and is not intended as a

substitute for medical advice, diagnosis, or treatment. Always seek the advice of a

qualified healthcare provider with any questions regarding a medical condition or before

making changes to your or your child’s care plan.