The gut-brain axis (GBA) is a dynamic, bidirectional communication system that connects the central nervous system (CNS) with the gastrointestinal (GI) tract. This intricate network is mediated by neural, endocrine, and immune pathways, and recent studies have highlighted the pivotal role of the gut microbiota in influencing neurodevelopment, cognition, mood, and behaviour. The gut microbiota, a complex ecosystem of microorganisms, plays a crucial role in maintaining the physiological functions of the GBA by modulating neurotransmitter levels, inflammatory responses, and hormonal signalling. Dysbiosis, an imbalance in the gut microbiota, has been implicated in various neurological and psychiatric disorders, including depression, anxiety, Parkinson’s disease, and Alzheimer’s disease. This systematic review synthesizes 20 recent studies on the GBA, focusing on its underlying mechanisms, the impact of gut microbiota on neurological disorders, and emerging therapeutic interventions. Clinical trials involving probiotics, faecal microbiota transplantation (FMT), and dietary interventions are examined, revealing promising therapeutic potential for treating GBA-related disorders. Future research should aim to further elucidate the molecular pathways and optimize interventions targeting gut health for improved neurological outcomes.

Gut-Brain Axis, Microbiota, Central Nervous System, Depression, Neuroinflammation, Parkinson’s Disease, Alzheimer’s Disease, Probiotics, Faecal Microbiota Transplantation