Gut-Brain Axis in ADHD: A Review of Current Evidence

Attention-Deficit/Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental disorder traditionally linked to monoaminergic dysregulation within the brain’s reward circuitry. Recent evidence points to the potential role of the gut-brain axis (GBA), a bidirectional communication network linking the central nervous system with the enteric microbiota. This narrative review explores the proposed associations between intestinal dysbiosis and ADHD symptoms, as well as the potential for GBA-targeted therapeutic interventions. Research suggests that individuals with ADHD may exhibit distinct microbial profiles, characterized by an increased abundance of genera such as Bifidobacterium and Bacteroides, and a depletion of anti-inflammatory taxa like Faecalibacterium. These shifts are hypothesized to contribute to “leaky gut” syndrome, potentially triggering systemic inflammation and neuroinflammation that could disrupt neural circuits responsible for executive function. Furthermore, experimental models indicate that gut microbes may modulate the availability of dopamine precursors, indirectly influencing reward processing. Preliminary clinical data suggest that “psychobiotics,” synbiotics, and targeted micronutrient supplementation (e.g., iron, zinc, and magnesium in cases of confirmed deficiencies) might serve as supportive interventions and potentially improve quality of life. While standard pharmacotherapy remains the primary treatment, GBA-focused strategies are being investigated as adjunctive therapies, offering a promising yet preliminary avenue for personalized management. Integrating these interventions may help manage common comorbidities across the lifespan, though further robust clinical trials are required.