Fig. 5: The complex interactions between gut microbiota and Parkinson’s Disease (PD) pathology.

Evtepia gabavorous reduces gamma-aminobutyric acid (GABA) production by consuming it, impacting neuronal excitability in brain regions, thereby exacerbating Parkinson’s Disease (PD) symptoms. Streptococcus anginosus generates H2S, which disrupts mitochondrial functions, elevating ROS levels and encouraging alpha-synuclein (αSyn) aggregation and prion-like spread via the vagal nerve. Moreover, Klebsiella variicola targets microglial cells, augmenting beta-amyloid and αSyn production, potentially intensifying PD progression through increased pro-inflammatory responses mediated by toll-like receptors. Created with BioRender.com.