CONNECTION BETWEEN GUT DYSBIOSIS AND GENERALIZED ANXIETY DISORDER: A NARRATIVE REVIEW
Abstract
Objective: This narrative review aims to summarize current evidence regarding the relationship between gut dysbiosis and Generalized Anxiety Disorder (GAD), with particular emphasis on alterations in gut microbiota composition, proposed biological mechanisms, and potential microbiome-targeted therapeutic strategies. Methods: A narrative review was conducted using thirteen peer-reviewed publications, including systematic reviews, narrative reviews, mechanistic studies, and clinical investigations examining associations between gut microbiota and anxiety disorders. The selected studies were analyzed to identify recurring microbiome-related findings, proposed mechanisms linking gut dysbiosis and anxiety, and evidence regarding microbiome-based interventions. Results: The reviewed literature consistently demonstrated significant associations between gut dysbiosis and anxiety disorders. Patients with GAD and related anxiety conditions frequently exhibited reduced microbial diversity, depletion of beneficial short-chain fatty acid-producing bacteria, and increased abundance of potentially pro-inflammatory taxa. Several studies highlighted disturbances in microbial metabolite production, neurotransmitter regulation, immune function, and stress-response pathways. Clinical investigations further revealed alterations in both microbial composition and microbial metabolic activity among individuals with anxiety disorders. Additionally, microbiome-targeted interventions, including probiotics, psychobiotics, and dietary modification, showed potential benefits in reducing anxiety symptoms, although findings remain heterogeneous. Conclusions: Current evidence supports a meaningful relationship between gut dysbiosis and anxiety disorders. Alterations in gut microbiota may contribute to anxiety pathophysiology through immune, metabolic, endocrine, and neurochemical mechanisms. However, the predominance of cross-sectional studies and methodological heterogeneity limit causal interpretation. Future longitudinal studies and randomized controlled trials are necessary to clarify causal relationships and evaluate the clinical utility of microbiome-based therapeutic interventions in Generalized Anxiety Disorder.