Microbiome and mind: current insights and future directions in gut-brain research

Recent research has increasingly focused on the relationship between gut microbiota and neurological disorders, revealing the broad role of gut microbiota in modulating various physiological and pathological conditions. The bidirectional communication between the brain and gut microbiota is now recognized as crucial for maintaining homeostasis. This gut-brain axis encompasses the central nervous system (CNS), neuroendocrine and neuroimmune systems; autonomic nervous system, enteric nervous system, and intestinal microbiota. Probiotics, which are live microorganisms similar to beneficial gut microbes, have been shown to modulate numerous conditions, including metabolic disorders, behavioral issues, and cognitive functions. Over the past decade, gut microbiota has emerged as a key regulator of brain processes and behavior. Diet significantly influences gut microbiota composition throughout life, and its impact on brain health via microbiota is gaining attention. Identified mechanisms of gut-to-brain communication include microbial metabolites, immune responses, neuronal signaling, and metabolic pathways, all potentially modifiable by diet. Animal studies on nutritional interventions targeting the microbiota-gut-brain axis have advanced our understanding of diet’s role in this complex interaction. This review summarizes current literature on the interplay between diet, microbiota, and host behavior/brain processes, explores underlying mechanisms, and discusses factors influencing dietary intervention responsiveness and the microbiota's role in modulating diet's effects on brain health.