American Ginseng Protein-Enriched Fraction Attenuates Neurobehavioral Deficits in MPTP-Induced Parkinson’s Disease Mice with Associated Modulation of Gut Microbiota and Metabolic Pathways

Background/Objectives: Parkinson’s disease (PD) currently lacks disease-modifying therapies. Available treatments offer only symptomatic relief and fail to halt progressive dopaminergic neuron loss. American ginseng (Panax quinquefolius L.) is a well-recognized functional food with documented neuroprotective properties, largely ascribed to its ginsenoside and polysaccharide fractions. However, its endogenous protein component, the American ginseng protein-enriched fraction (AGP), remains underexplored in the context of PD. This study aimed to investigate the neuroprotective effects of dietary AGP on PD and its association with the microbiota–gut–brain axis (MGBA).