Billions of microorganisms inhabit the human gut and maintain overall health. Recent research has revealed the intricate interaction between the brain and gut microbiota through the microbiota-gut-brain axis (MGBA) and its effect on neurodegenerative disorders (NDDs). Alterations in the gut microbiota, known as gut dysbiosis, are linked to the development and progression of several NDDs. Studies suggest that the gut microbiota may be a viable target for improving cognitive health and reducing hallmarks of brain aging. Numerous pathways including hypothalamic-pituitary-adrenal axis stimulation, neurotransmitter release disruption, system-wide inflammation, and increased intestinal and blood-brain barrier permeability connect gut dysbiosis to neurological conditions. Metabolites produced by the gut microbiota influence neural processes that affect brain function. Clinical interventions depend on the capacity to understand the equilibrium between beneficial and detrimental gut microbiota, as it affects both neurodegeneration and neuroprotection. The importance of the gut microbiota and its metabolites during brain aging and the development of neurological disorders is summarized in this review. Moreover, we explored the possible therapeutic effects of the gut microbiota on age-related NDDs. Highlighting various pathways that connect the gut and the brain, this review identifies several important domains where gut microbiota-based interventions could offer possible solutions for age-related NDDs. Furthermore, prebiotics and probiotics are discussed as effective alternatives for mitigating indirect causes of gut dysbiosis. These therapeutic interventions are poised to play a significant role in improving dysbiosis and NDDs, paving the way for further research.
