This is the 3rd blog post from The Embodied Mind series by Dr Alice Siberry.
Ever heard of having a “gut-feeling”? Long before modern neuroscience, there was an ancient belief that emotions came from the stomach. However, what we now know is that intuitive feeling you get arises from the complex communication between the brain and the gut. For neurodivergent people, this process can be even more complex. So, here’s what we know about the gut-brain link in neurodivergence so far…
Why the gut-brain connection matters
In recent years, scientists have learned that the gut and brain are in near-constant conversation. This communication happens through:
- Chemical signals
- Hormonal pathways
- The vagus nerve, a part of the parasympathetic nervous system, which directly connects the gut to the brain.
At the centre of this system is the gut microbiome; the trillions of microorganisms living in our digestive system (Taniya et al., 2022).
These microbes don’t just help digest our food. They also:
- Influence mood and stress responses
- Affect cognition and attention
- Regulate inflammation throughout the body
- Play a role in the production of neurotransmitters like dopamine and GABA, which are linked to mood, learning and sleep.
If you’ve ever felt irritable, foggy or emotional when hungry (hello, “hangry”), you’ve felt this system in action.
When the gut microbiome becomes imbalanced, due to stress, diet, disrupted sleep or illness, it can affect mental wellbeing and cognitive performance alongside regular digestion.
What this means for neurodivergent people
Research has found differences in the gut microbiome composition of neurodivergent people. While this doesn’t mean gut difference causes neurodivergence, it does suggest that gut physiology may play a role in experiences such as:
- Sensory processing
- Mood regulation
- Executive functioning.
Studies also show that neurodivergent people are more likely to experience dysbiosis, an imbalance that disrupts typical digestive function (Fattorusso et al., 2019; Feng et al., 2023).
This can show up as:
- Bloating, gas, diarrhoea or constipation
- Fatigue and brain fog
- Mood fluctuations
- Links to autoimmune or metabolic conditions.
Whilst dysbiosis is diagnosed, it cannot be diagnosed via a standard blood test. Microbiota must be analysed in a multi-disciplinary way, which can be challenging to access through traditional medical routes.
Food, sensory sensitivity and interoception
As well as the many digestive symptoms listed above, neurodivergent people are also more likely to experience a number of unique challenges related to food and diet. Food can be a sensory minefield. Texture, smell, temperature, flavour, packaging or even cutlery can trigger discomfort or overwhelm.
What is often labelled as “picky eating” is frequently a sensory response, not a behavioural choice. Research shows that autistic children, for example, may have strong sensitivities to:
- Specific textures or temperatures
- Colours or presentation of food
- Brands, packaging and utensils (Mirizzi et al., 2025).
These patterns often continue into adulthood. You may have noticed children and adults who prefer that foods never touch on their plate. Even a small overlap of textures can make them feel uncomfortable, anxious or even sick.
Interoception is our ability to notice internal bodily signals like hunger, fullness, nausea, pain and thirst. Some neurodivergent people experience significant challenges with interoception, making it harder to:
- Recognise hunger cues
- Notice fullness
- Identify digestive discomfort early.
This can contribute to restricted eating, irregular meals, or lead to diagnosable conditions such as ARFID (Avoidant/Restrictive Food Intake Disorder).
Add in executive functioning challenges, such as meal planning, shopping and cooking, it’s easy to see how nutrition and subsequent digestion can become another source of stress for neurodivergent people.
How digestive issues affect wellbeing
Digestive difficulties can have profound effects on daily functioning, attention, mood and overall quality of life. Discomfort, irregularity, or sensory challenges around food can amplify fatigue, stress and emotional dysregulation. Recognising the gut-brain link allows us to better support neurodivergent people in creating routines and interventions that honour both their digestive and neurological needs.
The gut is closely linked to the autonomic nervous system, which has 2 key branches:
- Parasympathetic nervous system: “rest and digest”
- Sympathetic nervous system: “fight or flight”
When the body is stressed, digestion slows down. Blood flow is redirected away from the gut, and gastrointestinal symptoms can worsen. There is growing evidence that many neurodivergent people spend more time in a heightened sympathetic (stress) state (Ferguson, 2017). This means that the body naturally may struggle to fully access the “rest and digest” system, making digestive discomfort more likely and more persistent.
One way to demonstrate this is in the case study of an autistic adult who loves pizza at home but struggles to eat the exact same pizza at a busy restaurant with friends and family. From the outside, it looks like “the same food”, leading to some confusion. The reality is that social expectations (to talk during the meal, to look at certain way whilst eating, knowing whether they can eat with their hands or whether they need to use cutlery), environmental noise (from other people in the restaurants, lights, people walking around them) and unpredictable stimuli (the occasional crash of a plate or glass!) activate the sympathetic nervous system, the body’s “fight or flight” response. When this system is heightened, the parasympathetic “rest and digest” system is suppressed, making it difficult to eat or enjoy food outside a safe, familiar environment.
Understanding this response shows why the challenge isn’t about preference, stubbornness or being “fussy” or “demanding”, it’s about how the body and brain interact under stress. Supporting the individual in this scenario might include environmental or social adaptations or flexible meal options, rather than assuming that the problem is the food itself.
Supporting gut health: what the research suggests
There’s no one-size-fits-all approach to support neurodivergent people and their gut health, and any changes should always be discussed with a healthcare professional. That said, research has explored several interventions:
- Probiotics and prebiotics: These may help restore microbial balance, reduce inflammation and ease gastrointestinal symptoms (Soleimanpour et al., 2024).
- Elimination diets: Some studies suggest removing gluten and/or casein may reduce gut inflammation for certain individuals (Baspinar and Yardimci, 2020).
- Low-FODMAP diets: FODMAPs are carbohydrates that can be hard to digest for some people. Reducing foods like wheat, onions, garlic and diary has been shown to ease gut symptoms in some cases (Nogay et al., 2021).
- Fibre intake: Fibre supports the productions of short-chain fatty acids, which play an important role in gut health.
- Vagus nerve stimulation: Practices that activate the parasympathetic nervous system may support digestion by encouraging the body into “rest and digest” mode.
What matters most is individualisation, respecting sensory needs, routines, access and capacity.
Bringing it all together
The gut-brain connection reminds that bodies and brains don’t work on separate systems. For neurodivergent people, digestive health is shaped not just by biology, but by sensory experiences, stress, nervous system regulation and everyday demands. When we take a whole-person view, rather than just looking at brain or body ‘symptoms’, we can create more realistic and effective support.
And that’s why sometimes listening to your gut really is listening to your brain.
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References
Baspinar B. & Yardimci H. (2020) Gluten-Free Casein-Free Diet for Autism Spectrum Disorders: Can It Be Effective in Solving Behavioural and Gastrointestinal Problems? Eurasian J Med. 52(3), 292-297. DOI: 10.5152/eurasianjmed.
Fattorusso A., Di Genova L., Dell’Isola G. B., Mencaroni E., Esposito S. (2019) Autism Spectrum Disorders and the Gut Microbiota. Nutrients. 11(3), 521. DOI: 10.3390/nu11030521.
Ferguson B. J., Marler S., Altstein L. L., Lee E. B., Akers J., Sohl K., McLaughlin A., Hartnett K., Kille B., Mazurek M., Macklin E. A., McDonnell E., Barstow M., Bauman M. L., Margolis K. G., Veenstra-VanderWeele J., Beversdorf D. Q. (2017) Psychophysiological Associations with Gastrointestinal Symptomatology in Autism Spectrum Disorder. Autism Res. 10(2), 276-288. DOI: 10.1002/aur.1646.
Feng, P., Zhao, S., Zhang, Y. and Li, E. (2023) A review of probiotics in the treatment of autism spectrum disorders: Perspectives from the gut-brain axis. Front. Microbiol. 14. DOI: https://doi.org/10.3389/fmicb.2023.1123462
Mirizzi P., Esposito M., Ricciardi O., Bove D., Fadda R., Caffò A. O., Mazza M., Valenti M. (2025) Food Selectivity in Children with Autism Spectrum Disorder and in Typically Developing Peers: Sensory Processing, Parental Practices, and Gastrointestinal Symptoms. Nutrients. 17(17) DOI: 10.3390/nu17172798.
Nogay N. H., Walton J., Roberts K. M., Nahikian-Nelms M., Witwer A. N. (2021) The Effect of the Low FODMAP Diet on Gastrointestinal Symptoms, Behavioral Problems and Nutrient Intake in Children with Autism Spectrum Disorder: A Randomized Controlled Pilot Trial. J Autism Dev Disord. 51(8), 2800-2811. DOI: 10.1007/s10803-020-04717-8.
Soleimanpour S., Abavisani M., Khoshrou A., Sahebkar A. (2024) Probiotics for autism spectrum disorder: An updated systematic review and meta-analysis of effects on symptoms. J Psychiatr Res. 179, 92-104. DOI: 10.1016/j.jpsychires.2024.09.009.
Taniya M. A., Chung H. J., Al Mamun A., Alam S., Aziz M. A., Emon N. U., Islam M. M., Hong S. S., Podder B. R., Ara Mimi A., Aktar Suchi S., Xiao J. (2022). Role of Gut Microbiome in Autism Spectrum Disorder and Its Therapeutic Regulation. Front Cell Infect Microbiol. 12. DOI: 10.3389/fcimb.2022.915701.