EFFECT OF A PROBIOTIC TREATMENT ON AN EXTENDED EARLY-STAGE PARKINSON’S DISEASE MODEL

The role of the gut microbiota (GM) on Parkinson’s disease (PD) pathogenesis has been a main focal point of research in recent years. The characterisation of the involvement of the gut-brain axis in the aetiology of the disease has illustrated a direct association of GM health with parameters such as immunity and inflammation, a-synuclein aggregation, intestinal barrier permeability, motor function, and metabolism, that are likely to play a role in PD pathology and clinical presentation. Targeting and maintaining a homeostatic GM may therefore lead to a potential prevention or alleviation of PD symptoms. The aim of this project was to identify the effects of an oral probiotic treatment on early-stage PD using a toxin-induced PD rat model with a focus on early motor dysfunction, neurodegeneration, neuroinflammation, plasma cytokine levels and short chain fatty acid (SCFA) levels. Probiotic treatment was shown to significantly alleviate the motor deficit observed in the PD model and partially prevented tyrosine hydroxylase (TH)-positive cell loss in the substantia nigra pars compacta (SNpc) of the PD models. Treatment with probiotics also increased SCFAs levels in the treatment groups, reduced plasma levels of inflammatory cytokines and lipopolysaccharides (LPS), reduced cortical and hippocampal neuroinflammation and reduced levels of a-synuclein. This study therefore supports sustained probiotic intervention as a promising strategy to attenuate disease progression during the early stages of PD, warranting further mechanistic and translational investigation.