A comprehensive review on immunological mechanisms and gut-brain pathways linking gut health and neurological disorders

The gut-brain axis represents a complex communication network linking the gastrointestinal system and the central nervous system (CNS). Emerging evidence highlights the role of gut health in influencing neurological disorders through various immunological mechanisms. Despite this recognition, a comprehensive and integrated elucidation of the specific immunological pathways linking gut health to the broad spectrum of neurological disorders remains a research gap. This review addresses this by providing a novel, holistic synthesis of these intricate immunological connections, aiming to elucidate these immunological pathways that connect gut health with neurological disorders, including conditions such as depression, anxiety, autism spectrum disorders, and neurodegenerative diseases. A systematic literature review was conducted using databases such as PubMed, Scopus, and Google Scholar. Studies investigating the interplay between gut microbiota, immune response, and neurological outcomes were identified, with key analyses focusing on cytokine profiles, the role of the gut microbiome, and alterations in the blood-brain barrier (BBB). Findings indicate that dysbiosis of gut microbiota can lead to an altered immune response, characterized by increased levels of pro-inflammatory cytokines, which may compromise the integrity of the BBB. Such changes are linked to neuroinflammation and may contribute to the pathophysiology of various neurological disorders. Furthermore, the gut microbiome has been shown to influence neurotransmitter synthesis and modulate neuroinflammatory pathways. This review highlights the critical role of immunological mechanisms in linking gut health to neurological disorders. Understanding these connections may open new therapeutic avenues for treating neurological disorders through modulation of the gut microbiome and immune system. Future research should focus on targeted interventions aimed at restoring gut health to prevent or mitigate the effects of neurological conditions.