Decoding Communication Difficulties in ADHD: A Narrative Review on the Potential Links with Dietary Patterns, the Microbiome, and Oxidative Stress

Background/Objectives: Individuals with attention-deficit/hyperactivity disorder (ADHD) often experience communication difficulties (CDs), including challenges with language development, pragmatic communication, and speech processing. While these difficulties are typically associated with cognitive and behavioral symptoms; emerging research suggests that biological and nutritional factors may also contribute. This narrative review aims to explore how diet patterns, gut microbiome changes and oxidative stress might be associated with communication difficulties in ADHD. Methods: This review was performed using the SANRA (Scale for the Assessment of Narrative Review Articles) framework. A structured/comprehensive literature search was performed across major databases including PubMed, Scopus and Web of Science. Google Scholar has been utilized as a complementary database to support emerging studies that have not yet been registered in these databases. The search focused on studies that investigated the connections between nutrition, microbiome dysregulation, oxidative stress, ADHD and communication-related outcomes. Results: Current research indicates that unbalanced diets, micronutrient deficiencies, and changes in the gut microbiome can lead to neuroinflammation and oxidative stress. All these biological processes may disrupt neurotransmission and neural connectivity, which can potentially affect brain regions and networks that are highly important for attention and language processing, including both cortical and subcortical structures. Therefore, communication difficulties in ADHD may, in part, stem from these interconnected neurobiological mechanisms. However, direct clinical evidence linking nutritional factors, gut microbiome alterations, or oxidative stress with communication-specific outcomes in ADHD remains very limited, as most available studies have focused on core ADHD symptoms, attention, executive functioning, or biological markers. Conclusions: Dietary factors, alterations in the gut microbiome, and oxidative stress may collectively contribute to the complex underlying causes of communication disorders in ADHD. This review proposes an integrative framework that links nutrition-related mechanisms to communication outcomes, emphasizing the potential impact of modifiable lifestyle factors. Further longitudinal studies are needed to establish causal relationships and determine the clinical effectiveness of targeted nutritional interventions for communication difficulties in ADHD.