The human microbiome consists of over one thousand strains of bacteria, fungi, viruses, and protists in the gastrointestinal tract.  The microbiota continually changes from birth; it is considered settled by the age of three.  During an individual’s lifetime, an individual is constantly exposed to challenges such as unhealthy diet, medications, and infections. Therapies to maintain pre-challenge baselines can be guided by the knowledge of what microbial species or functions are perturbed by challenges and designed to replace diminished species with probiotics, when available, or boost them with prebiotics. Many studies are currently focused on the levels of bifidobacteria, as it is recognized as a marker of intestinal health. Environmental factors and genetics can cause an imbalance in the gut microbiome, known as dysbiosis.  These imbalances can cause several age-associated changes, including susceptibility to diseases and immune dysregulation.  Thus, the gut microbiome can have a pivotal role in etiopathology and neurological disease progression.  However, currently, there is a significant gap in the knowledge regarding the involvement of specific gut microbiome correlating to the enhanced risk of neurodegeneration. Subsequently, PubMed, Scopus, and Google Scholar databases were searched till June 2022, using suitable keywords to fill in the scientific lacuna.  The gut microbiota undergoes extensive changes across the lifespan, and age-related processes may influence the gut microbiota and its related metabolic alterations.  Overall, numerous neurological diseases are affected by dysbiosis, and a causal relationship has been observed.  Thus, elucidating the role and mechanisms of the gut microbiome on the etiopathology of neurodegeneration is imminently required.  Consequently, the gut microbiome can be used as a diagnostic and prognostic target to develop therapeutics.

Keyword : Microbiome, Neurodegeneration, Gut