Parkinson's disease (PD) is a progressive neurodegenerative disorder with an increasing prevalence in the aging population. Current therapeutic approaches are largely symptomatic, and disease-modifying treatments capable of halting or slowing disease progression remain limited. This has led to growing interest in complementary and supportive strategies for the management of PD. In recent years, nutrition-related factors, particularly the gut microbiota, have attracted considerable attention due to their potential influence on the pathogenesis and clinical course of the disease. The microbiota-gut-brain axis, which describes the bidirectional communication between the gut microbiota and the central nervous system, is closely associated with key pathophysiological mechanisms of PD, including neuroinflammation, oxidative stress, and α-synuclein aggregation. Alterations in gut microbiota composition in individuals with PD have been reported to be associated with both motor and non-motor symptoms. In this context, microbiota-targeted interventions have emerged as a potential approach in disease management. Experimental and clinical studies suggest that probiotic supplementation may contribute to the improvement of gastrointestinal symptoms in patients with PD and may exert beneficial effects on certain neurological outcomes. However, evidence regarding the therapeutic efficacy of probiotics in PD remains limited, and further studies are required to clarify underlying mechanisms and strengthen clinical evidence. This narrative review aims to evaluate the therapeutic potential of probiotics in PD in light of current experimental and clinical evidence and to discuss possible mechanisms of action through the microbiota-gut-brain axis.
