Prebiotics and Mental Health: Current Evidence and Emerging Perspectives

Neuropsychiatric disorders such as schizophrenia, attention deficit hyperactivity disorder (ADHD), and autism spectrum disorder (ASD) pose complex challenges to cognition, behaviour, and emotional regulation, with rising rates of treatment resistance further complicating management. Emerging evidence implicates the gut microbiome, acting through the gut–brain axis, in the pathophysiology of these conditions. Prebiotics, non-digestible compounds such as inulin and fructo-oligosaccharides, promote the growth of beneficial gut bacteria and enhance the production of short-chain fatty acids (SCFAs), neurotransmitters including serotonin, dopamine, and other metabolites that support neural function and emotional health. Preclinical studies, including maternal immune activation models in mice, demonstrate that prebiotic supplementation can mitigate cognitive deficits and behavioural abnormalities associated with microbial dysbiosis. Although human clinical trials remain limited, early findings suggest that dietary prebiotic interventions may improve symptoms in selected neuropsychiatric populations. Key challenges persist, however, including inter-individual variability in microbiome composition, optimal dosing strategies, and long-term efficacy. This review synthesises current evidence on the role of prebiotics in neuropsychiatric disorders, highlighting underlying mechanisms, therapeutic potential, and the need for personalised treatment approaches. It emphasises the importance of longitudinal, well-powered studies to translate preclinical findings into effective, microbiome-targeted adjunctive therapies for neuropsychiatric conditions.