Intestinal dysbiosis leads to the reduction in neurochemical production in Parkinson's disease (PD).

Parkinson's Disease (PD) is a neurodegenerative disorder characterized by motor and non-motor symptoms, with emerging research suggesting a critical link between intestinal dysbiosis and PD progression. This review explores the pathophysiological mechanisms underlying PD, such as alpha-synuclein aggregation, mitochondrial dysfunction, neuroinflammation, and oxidative stress, while focusing on the impact of gut dysbiosis on intestinal barrier function and its role in reduced neurochemical production. The clinical features of PD, including dopamine, serotonin, and GABA deficiencies, are examined, with a focus on how dysbiosis contributes to neurotransmitter depletion. Current treatments of PD, such as levodopa and dopamine agonists, are discussed alongside gut health therapies such as probiotics, prebiotics, and Fecal Microbiota Transplantation (FMT). Future therapeutic directions, including synbiotics, engineered microbes, phage therapy, and the integration of machine learning (ML) and artificial intelligence (AI), are explored. The chapter also considers preventive strategies, such as lifestyle adjustments and early gut health monitoring using modern diagnostic tools and biosensors. Furthermore, a strong need for continued research into the gut-brain axis (GBA) to develop more effective, gut-targeted therapies for managing PD is discussed.