Figure 2.

Parkinson's disease. Dysbiosis and leaky gut often occur with age, allowing contents of the gut lumen, such as curli from E. coli biofilms, to escape and induce changes in the brain through the gut-brain axis. Curli may contribute to Parkinson's Disease by increasing systemic inflammation and neuroinflammation in the form of activated microglia and astrocytes and elevated pro-inflammatory cytokines. Curli may also cross-seed fibrillation and aggregation of α-synuclein, which is capable of prion-like propagation from the gut to the brain to cause neurodegeneration.