The Role of the Gut Microbiome in ADHD - Current Evidence
ADHD is one of the most prevalent neurodevelopmental and neurobehavioral disorders in children and adolescents, however there is still little known about the underlying causes. ADHD is commonly characterized by hyperactivity and impulsivity, inattentiveness, or a combination of all three—however, that can look very different from patient to patient. Research is now looking deeper with studies linking common traits displayed in ADHD patients to the microbiome (or gut).
Individuals diagnosed with ADHD often experience a higher prevalence of gastrointestinal problems. They commonly face challenges related to immune dysregulation, mild inflammation, nutrient deficiencies, and poor gut health. These symptoms indicate that negative signals may be sent from the microbiome to the brain, highlighting the intricate connection between gut health and neurological conditions like ADHD.
Our gut and brain are closely linked through the “microbiota–gut–brain axis” (MGBA). Microbes in our gut can communicate directly with our nervous system and other body systems. When the gut is not healthy (or imbalanced) it sends different messages that differ to messages sent from a healthy gut.
The consequences of a dysregulated gut are the most obvious ways the microbiome may be implicated in ADHD. But gut bugs are also increasingly implicated in another significant hallmark of the disorder— a dysfunction of the brain’s reward pathway, this is where dopamine comes in. This dopamine pathway plays a critical role in regulating feelings of pleasure, motivation, learning and reinforcement of certain behaviours. To function properly this pathway relies upon production of the neurotransmitter dopamine. When we engage in rewarding activities or experience positive reinforcement, dopamine is released, which is a “feel good” or “pleasure” chemical in our brain.
Beneficial gut bacteria can synthesise dopamine precursors, supporting dopamine availability in the brain. Additionally, a healthy gut environment fosters efficient nutrient absorption, including vitamins and amino acids essential for neurotransmitter production. When gut health is compromised, such as through dysbiosis or inflammation, dopamine production and signaling can be disrupted, potentially exacerbating ADHD symptoms. These insights provides useful targets for treatment of ADHD symptoms by focusing on the gut.
Probiotics and Gut Health:
Specific probiotic strains have been well researched and show positive results in managing symptoms common to ADHD individuals. Optimising gut microbes targets multiple avenues of the gut brain axis communication for ADHD individuals and is a safe and effective way of improving cognitive function and behaviour
Dietary Interventions:
Nutritional approaches and diet are crucial when supporting a healthy gut and brain. Eating predominantly whole foods and avoiding processed foods and artificial additives is vital in reducing symptoms. Specific food groups are essential for ADHD individuals and food intolerances need to be accounted for.
Nutritional Supplements:
Naturopaths often recommend supplements to support brain health. Omega-3 fatty acids, magnesium, zinc, and iron are vital nutrients that play a role in neurotransmitter regulation. These supplements, when combined with a balanced diet, can enhance focus and cognitive function in individuals with ADHD and can also reduce unwanted behaviours.
Testing:
Microbiome testing is a great way to examine whats going on in the gut and allows for an individualised treatment plan. Specific bacterial overgrowths can have huge effects on someone with ADHD, which then further impacts gut health, nutrient status and brain health.
Although more research is needed in this field there is still an overwhelm of evidence to suggest supporting a healthy microbiota–gut–brain axis is highly beneficial in managing symptoms. Gut health needs to be treated on an individual basis, diet, nutrient deficiencies, lifestyle practices are all essential when developing treatment options. It’s important you speak with a professional such as a Naturopath or Nutritionist, who is experienced in microbiome health.
If you would like to investigate this topic more here are some great references:
Checa-Ros, A., Jeréz-Calero, A., Molina-Carballo, A., Campoy, C., & Muñoz-Hoyos, A. (2021). Current Evidence on the Role of the Gut Microbiome in ADHD Pathophysiology and Therapeutic Implications. Nutrients, 13(1), 249. https://doi.org/10.3390/nu13010249
Mathee, K., Cickovski, T., Deoraj, A., Stollstorff, M., & Narasimhan, G. (2020). The gut microbiome and neuropsychiatric disorders: implications for attention deficit hyperactivity disorder (ADHD). Journal of medical microbiology, 69(1), 14–24. https://doi.org/10.1099/jmm.0.001112
Wang, L. J., Yang, C. Y., Kuo, H. C., Chou, W. J., Tsai, C. S., & Lee, S. Y. (2022). Effect of Bifidobacterium bifidum on Clinical Characteristics and Gut Microbiota in Attention-Deficit/Hyperactivity Disorder. Journal of personalized medicine, 12(2), 227. https://doi.org/10.3390/jpm12020227