Gut–Brain Axis: Role of Gut Microbiota on Neurological Diseases and How Probiotics/Prebiotics Beneficially Modulate Microbial and Immune Pathways to improve Brain Functions

Abstract The gastrointestinal tract (GIT) has the largest and most vulnerable surface, and the gut microbiota plays a crucial role in observing meals, nutrients, and environmental variables as well as differentiating commensals from invasive infections.In the context of health and illness, it is commonly known that the stomach and the central nervous system (CNS) are closely related. A healthy gut with a diverse range of bacteria is essential for normal brain and emotional functioning. Most of the gastrointestinal physiology is also under direction of the central nervous system. Gut homeostasis and healthy digestion are maintained by the intricate and reciprocal molecular interactions between the gut/microbiome and the central nervous system. A number of other processes, including as neuronal, endocrine, toll-like receptor, and metabolite-dependent pathways, have also been hypothesized. Since the pathophysiology of neurological and gastrointestinal problems is associated with changes in the reciprocal interaction between the GIT and CNS, the microbiota/gut-and-brain axis is a new and well recognized idea. In this review, we highlight the most current research demonstrating the immune system and gut microbiota's roles in both the development of neurological illnesses and the preservation of brain function. Furthermore, using the gut–brain axis idea, we emphasize the current developments in the treatment of neurological disorders through the use of probiotics, prebiotics, synbiotics, and fecal microbiota transplantation.