Autistic kids (and adults) often have very specific diets, with short lists of “safe foods” and extreme discomfort with trying anything outside that list.
Autistic individuals also often have chronic problems with their digestive systems, including stomach pain and acid reflux.
A new study examined the relationship between the two phenomena, and researchers believe that the dietary restrictions are a causal factor in altered gut bacteria, which in turn cause not only digestive discomforts, but also inflammatory responses that may drive some of the other traits associated with autism, including anxiety and repetitive behaviors.
Confirming this and carrying out further research has the potential to make life a little more comfortable for autistic kids (and adults).
The Microbiome Of The Gut
Everyperson’s body is full of microbiotic organisms that work to keep digestion and other functions in order. Upsetting this balance can cause gastric problems (bloating, constipation, etc), weight fluctuations, food cravings, and even alter the function of neurotransmitters and disrupt serotonin production!
Studies on the association between autism and gut microbiome have been carried out for at least a few decades, but the more that researchers dig in, the more they’re making the connection.
This latest study examines the causal link between autistic dietary restrictions or limitations and gut microbiome.
To be clear, this doesn’t suggest that restricted eating “causes” autism, or that kids (or adults) can be “cured” of autism by altering the gut microbiome, nor does it even remotely suggest that forcing a different dietary standard on autistic kids is a good or healthy idea!
However, solidifying the link could lead to alternative methods of bringing the gut biome back to a more typical balance could potentially reduce some of the stomach upset and inflammation that make certain symptoms of autism more uncomfortable and severe.
The Dietary Link
Autistic people can have a difficult time with eating. A variety of factors contribute to this, which can include underdeveloped oral muscles, the sensory sensations attached to certain foods, or the sensory aspects of being required to sit at a table and join in the group activity of a family meal, according to Child Mind. The digestive struggles many autistic kids have are also a factor.
Unfortunately, the digestive struggles can be a cyclic problem, because in turn, the limited diet can make them more severe.
A new study published in Nutrients found that the gut microbiota of autistic children can be altered through the dosage of probiotics, and through a rotational or elimination diet. More specifically, these interventions changed microbiota that affect inflammation and barrier functions in the digestive system.
“Dietary interventions combined with probiotics appear to be associated with microbiota modulation and a tendency toward improvement in markers of intestinal inflammation and barrier function.”
What’s The Relevance Of This Inflammation & Microbiota?
Autistic people are more likely to have digestive difficulties, including stomach pains, diarrhea, and constipation, among other symptoms. However, we also know that these symptoms, as well as digestive system inflammation, and, specifically, a gut biome that’s out of balance, have effects on mental health.
For instance a review published in Cureus last year notes a bidirectional link between gut microbiota and mental health.
It covers some of the ways that gut microbiota and inflammation affect the immune system, which in turn has effects on neurotransmitters, increasing the symptoms of depression and anxiety, and how intestinal permeability (those barrier functions we were discussing above, commonly called “leaky gut”) can result in harmful substances entering the bloodstream, which in turn affects the neuroimmune system and increases symptoms of depression.
A separate study, published in Molecular Autism in 2024, more directly addresses the links between gastrointestinal issues and certain traits common in autistic people.
“GI issues interact with other conditions and may worsen sleep problems and increase rates of self-injurious and aggressive behaviours, particularly among non-verbal autistic children. Higher rates of internalising symptoms, including anxiety and social withdrawal, which present at elevated rates in the autistic population, have a bidirectional relationship with GI problems such as constipation, diarrhoea, nausea, and stomach pain.”
So, Are Probiotic Meds & Diet Changes The Cure For Autism?
No. Autism is a neurotype and is predominantly caused by genetic differences. You cannot make your autistic child stop being autistic.
Instead, it’s possible that research can lead to some interventions that make some of the traits or symptoms associated with autism, the ones that are inconvenient, uncomfortable, or even painful for your child, less so.
If research continues to support these findings, it’s possible that conscious choices to change the gut biome could reduce symptoms of anxiety and depression in some people, and, potentially, some of the sensory sensitivities and social discomforts of autism.
Should I Change My Kid’s Diet, Then?
Major dietary changes should only be done with guidance from your child’s doctor.
Forcing your child to eat foods he does not like will not cure his autism, or ‘fix’ his gut biome. This study involved close monitoring of children’s gut microbiome during the dietary changes.
If your child is not getting the nutrients he needs from his diet, then introducing foods that will help provide them is always a good idea, but, especially for autistic children, this must be done with sensitivity and understanding, not forced or pushed.
Forcing your autistic child to eat foods that are outside his comfort zone can cause new problems. Encouraging your autistic child to try new foods is great, but remember that your child is likely not just “being picky.” They are reacting to sensory and other messages from their bodies, and being forced to ignore them can be upsetting and even traumatic.
What Should Parents Do?
If you are worried about your child’s diet and/or gut microbiome, talk to your pediatrician about changes that may be needed, and how to handle them gently.
Monitor your child for gastrointestinal symptoms, like frequent stomachaches, acid reflux, constipation, and other discomforts, and speak to your pediatrician about any needs in this area.
Remember that your child may not speak up about these, and that autistic kids can often ‘mask’ pain and discomfort, or may not even be consciously aware of them.
That means these symptoms may show up as behavior, instead of as “Mom? My tummy hurts.” (This is especially true for kids who have had chronic stomach pains downplayed or ignored, but can apply to any kid.)
In the meantime, parents can keep an eye on this space for any updates from gut microbiome and autism research. As research continues, developments may make new options available.
For now, there is no proven probiotic or dietary treatment for mental health conditions or physically uncomfortable symptoms of autism, but the research suggests that there could be some soothing in the future.
