Part 2: Neurodivergence, IBS and types of food reactions

This blog is a continuation from part 1

Supports, testing and accommodations

The table below shows some of the common challenges I see in the clinic and how I support these in an Neurodivergent-affirming way:


Motor dysfunction, motility issues and the vagus nerve:

Oral motor:

This refers to the difficulties coordinating the muscles of the mouth, palate, throat and oesophagus which can result in feeding difficulties in Autistic and ADHD children and adults(Maffei et al, 2023)(Gilbert et al. 2011).

Neurodivergent people may struggle with eating or swallowing certain textures and may have a preference for soft foods. Also commonly reported are difficulties with swallowing tablets or capsules, and having medications or supplements resurface minutes after swallowing them, even if after a meal.  

They may also have experienced choking, vomiting, regurgitation or reflux and develop a trauma-type fear response which will result in the avoidance of certain food groups. 

Vagal motor outflow:

Our brain talks to our digestive system via the vagus nerve. Disrupted vagal motor outflow (nerve signals from the brain through the vagus nerve) can impair intestinal movement and also result in gut hypersensitivity. 

Signs:

  • Chronic constipation ‘sluggish digestion’ that can be quite treatment resistant

  • SIBO (small intestinal bacterial overgrowth)

  • Indigestion

  • GI pain and sensitivity

  • Gut inflammation

  • Bloating and cramping

Conclusion:

Neurodivergent people can have a multitude of gut and food reactions which vary and fluctuate making life unpredictable and symptoms difficult to manage. 

This can be confusing and scary to the ND person and their healthcare practitioners because symptoms may calm down or flare up idiosyncratically depending on the state of their nervous system and stress (perceived sense of safety), sleep levels, environmental changes or hormone cycle.

Common examples from clinic include people being able to tolerate known problem-foods when abroad on holiday (i.e. gluten, dairy), or sudden IBS flare ups on anniversaries of bereavements or other notable dates of grief.

Communication differences and a general lack of practitioner training in how interoception affects IBS, digestive sensations, hunger/satiety signals, and food reactions means that key symptoms could be misunderstood or not taken seriously based on descriptions that do not match the provider’s expectations. 

Research in the neurodivergent gut microbiome (particularly autism) often finds low bacterial diversity, and this usually reflects diets that are low in fermentable fibres. Many ND people have repetitive diets due to safety and predictability in same-foods and routines, or struggle with the sensory aspects and textures of fibre foods/wholegrains. For people who are able to modify their diet, this can result in improvement in their gut health, however simply changing the diet is not accessible to all and can be harmful if insisted upon. 

It can be empowering to learn about the role of food intolerances, gut inflammation, metabolic imbalances and their knock-on effects on a wide range of health problems such as fatigue and to know our options in breaking these vicious cycles.  However this can equally be disempowering if the solutions require huge dietary and lifestyle changes with no consideration for the barriers ND people might face such as executive functioning difficulties.

Practitioners often need to think outside of the box in anti-ableist ways, destigmatizing the use of accommodations (such as supplements, convenience and processed foods) and reduce shame and blame associated with poor health.

Claire Sehinson