“There seems to be a link between foreign microbes, be they virus or bacteria, and the triggering of synucleinopathy.”

"The current study stops short of linking nasal infection with changes in α-synuclein; however, the method opens the door to future studies on how microbes affect α-synuclein expression and metabolism."

AlzForum article: Olfactory System Model Explores Antimicrobial Role for α-Synuclein, 12 May 2017.
Olfactory System Model Explores Antimicrobial Role for α-Synuclein | ALZFORUM

Open-access research paper: Holocranohistochemistry enables the visualization of α-synuclein expression in the murine olfactory system and discovery of its systemic anti-microbial effects, Tomlinson et al., J Neural Transm (Vienna). 2017 Jun;124(6):721-738.
Holocranohistochemistry enables the visualization of α-synuclein expression in the murine olfactory system and discovery of its systemic anti-micro... - PubMed - NCBI