The gut-brain axis (GBA) is the bidirectional cross-talk between the gut microbiome and the central nervous system with the gut microbiota being the key regulator. Τhe GBA axis includes nerve, neuroendocrine, and immune pathways highlighting its central role in diverse neuropsychiatric disorders, such as the attention deficit/hyperactivity disorder (ADHD). Today ADHD is the most prevalent neurodevelopmental disorder with unknown aetiology and extremely challenging diagnosis and treatment.
Compelling evidence supports a strong link between the gut microbiota and ADHD development. Gut microbiota has a great impact on the immune and neuroendocrine systems during the developmental critical periods in childhood when is the ADHD onset. Gut microbiota can directly or indirectly produce neuromodulators, like dopamine and serotonin, that can control dysfunctional behaviours and emotional regulation in ADHD. Additionally, patients with ADHD commonly manifest gastrointestinal symptoms, have an altered intestinal microbial genera, and specific dietary food known to modulate gut composition correlates with ADHD risk. Children with ADHD have significantly lower levels of omega-3 PUFAs and omega-3 PUFAs supplementation improves their inattention and hyperactivity symptoms by influencing their gut microbiota.
Modern life and its consequent changes in the dietary food, habits and lifestyles, have greatly impacted the gut flora increasing the neuropsychiatric disorder risk. Manipulations of the gut microbiome represent a promising therapeutic and preventive target in ADHD onset and development.