Does ‘biome depletion’ cause ADHD?
The first factor that researchers believe alters the gut microbiome is what’s referred to as “biome depletion”. This is a loss of certain gut bacteria that has been suggested to contribute to not only autoimmune diseases but also conditions like autism, and possibly ADHD.
The ‘biome depletion hypothesis’ suggests that beneficial gut bacteria have co-evolved with humans over hundreds of thousands of years to regulate and stabilize immune function. And that our lifestyle and dietary habits are what’s responsible for the reduced diversity in these symbiotic gut microbes.
Things like an ultra-hygienic environment, increased antibiotic usage, and lack of exposure to beneficial microbes disrupts the microbiome in a way that results in a lack of immune competence. And that, in turn, increases the risk of autoimmune disease, food sensitivities, autism spectrum disorder, ADHD, and a host of other problems.
Changes in gut bacteria are also linked to an increase in leaky gut, which research suggests is a key trigger for food sensitivities. People with ADHD are also more likely to experience food sensitivities than those without (7).
Diet and other environmental factors do play a role in ADHD and ASDs
The second factor contributing to the development of these disorders is an environmental trigger. This includes a potentially very long list of diet and lifestyle factors, which may be:
- Poor diet (Standard American Diet, or a lack of healthy foods)
- High consumption of refined and processed foods (including food additives, sugar, and artificial colors)
- Increased antibiotic use
- Vitamin D deficiency
- Low intake of essential fatty acids
Children with ADHD have been shown to have a higher deficiency in essential fatty acids (such as omega-3s) despite consuming similar amounts of EFAs as those without ADHD (8). Similarly, supplementation with high-dose omega-3 has been shown to help manage ADHD symptoms in both children and adults.
Related: Brain Health, ADHD, and Omega-3s
A genetic predisposition to ASD or ADHD
Obviously, not all kids with a less-than-healthy diet or who were exposed to (and needed) antibiotics at a young age have ADHD or ASDs. So why do some children have this experience and other kids do not?
This is where genetics and epigenetics come in.
You may have heard the role of epigenetics explained like this: Adding eggs, butter, and flour to a bowl doesn’t automatically produce a cake. But if you combine them in a certain way and perform the necessary actions, the result is a cake. Your genes in this case provide the ingredients, but your environment and personal choices control the outcome to a large extent.
Epigenetics is the study of how your behaviors and environment influences which genes get expressed, and which do not. For some people, a combination of ingredients (genes), paired with an environmental trigger, may result in the development of ADHD or ASDs.
How does Sugar affect ADHD symptoms?
The role of diet in ADHD is a complex one. While some studies have found no correlation with sugar intake and ‘hyperactivity’, others have shown that the more sugar a child with ADHD consumes, the more restless and destructive they become (9).
So, while sugar itself isn’t likely to cause ADHD symptoms, it does appear that it can worsen them in children who already struggle with attention issues.
There is also some evidence that certain food additives can contribute to hyperactive behavior, although again, it’s not clear if this is cause and effect or just an association.
A diet high in refined foods and low in essential minerals can contribute to an imbalance in neurotransmitters, such as GABA and glutamate.
GABA, or gamma aminobutyric acid, is an amino acid and neurotransmitter that calms the brain, while glutamate is more excitatory in nature, stimulating the brain and sometimes putting it in overdrive.
Low GABA levels are associated with ADHD (10). Low GABA is usually accompanied by inattention while high glutamate levels can lead to aggression and impulsivity. GABA, like serotonin, is primarily manufactured in the gut.
Artificial colors & food additives
Red dye #40 is a synthetic food dye made from byproducts of petroleum. It is linked to certain ADHD symptoms, such as hyperactivity, and may cause neurological effects in children (11). While small amounts are generally considered safe for consumption, some children may be more sensitive to its effects than others.
Will restoring gut microbiota cure ADHD symptoms and ASD?
The simple answer is that there is no ‘cure’ for ADHD or ASD, and even if we could restore the gut microbiota, it’s unlikely that these conditions would be completely cured.
We do know that the gut microbiota plays a role in both ADHD and ASD, but we don’t yet know if restoring the microbiota would completely reverse these conditions or help alleviate some of the symptoms.
It is possible that restoring the gut microbiota, improving the diet, and optimizing overall health could help alleviate some of the symptoms of these conditions, and this is something that warrants further investigation.
The bottom line on diet and ADHD
So what does all this mean? Well, first of all, it means that there is no singular cause of ADHD or autism spectrum disorders.
These are complex disorders with a variety of possible underlying causes. And that’s why integrative medicine approaches like functional medicine are so important.
Functional medicine is all about identifying and addressing the underlying root causes of disease, rather than just treating the symptoms. In the case of ADHD and autism spectrum disorder, some of the underlying root causes may include things like:
- Microbiota depletion
- Poor diet
- Nutrient deficiencies
- Exposure to toxins
By addressing these underlying causes, we can often improve symptoms. If you or someone you know is struggling with ADHD or autism spectrum disorder, there is hope. Contact a patient care coordinator today to learn more about how we can help.
Working with an integrative provider
The gut microbiome has been implicated in a range of chronic diseases, including autism spectrum disorders and ADHD. While the research is still emerging, it’s clear that diet and lifestyle can play a role in shaping the gut microbiome, and thus brain function. To promote a healthy gut microbiome, eat a healthy diet of vegetables, fruits, and minimally processed grains; drink plenty of water; get regular exercise; and reduce stress in your life. It’s also important to avoid antibiotic overuse and exposure to environmental toxins.
If you are struggling with symptoms related to ADHD or an ASD, it’s important to consult with a qualified integrative practitioner who can help you develop a treatment plan that works for you.