Therapeutic role of probiotics in motor and non-motor symptoms of Parkinson’s disease

Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by motor and non-motor symptoms, in which gut microbiota alterations have emerged as a potential pathogenic factor, causing disruption of the brain-gut-microbiota (BGM) axis. Recent evidence supports the role of BGM axis disruption in enhancing neuroinflammation, alpha-synuclein (α-syn) aggregation, and dopaminergic neurodegeneration. Emerging therapeutic strategies targeting dysbiosis, such as probiotics and fecal microbiota transplantation (FMT), have become a new focus of investigation for PD treatment. Proposed mechanisms include modulation of immune responses, enhancement of intestinal barrier integrity, production of neuroactive metabolites such as short-chain fatty acids, and reduction of oxidative stress. This narrative review summarizes current evidence on probiotics as a therapeutic strategy in PD. By analyzing data from randomized controlled trials and preclinical studies, we highlight the beneficial effects of probiotics in improving motor and non-motor symptoms of PD, including constipation, depression, and anxiety. Strains such as Lactobacillus plantarum PS128 and Bifidobacterium animalis Probio-M8 show particular promise. Although probiotics have demonstrated a favorable safety profile and potential as an adjunctive therapy for PD, future research should focus on standardized protocols, biomarker identification, and exploration of combined microbiota-targeted strategies.