> Dr Sampson has tested this hypothesis in mice. He bred a strain of E. coli that cannot make Curli and injected mice with it, while injecting others with unmodified bacteria. Those that received Curli-producing bacteria expressed higher levels of synuclein and demonstrated symptoms like involuntary rigidity which, when seen in people, are associated with Parkinson’s disease. That is tantalising.
These mice were mono-colonized with E. coli, whereas both mice and humans normally have a diverse gut flora. I colonize mice with E. coli containing curli all the time and the mice do not exhibit any rigidity or symptoms of Parkinson's. So it's interesting but not quite as huge of an effect as you might think, unless your microbial flora is really disrupted. May be relevant if you have an antibiotic resistant strain of E. coli blooming in your intestine following antibiotic treatment/some other disruption of your microbiota.
These mice were mono-colonized with E. coli, whereas both mice and humans normally have a diverse gut flora. I colonize mice with E. coli containing curli all the time and the mice do not exhibit any rigidity or symptoms of Parkinson's. So it's interesting but not quite as huge of an effect as you might think, unless your microbial flora is really disrupted. May be relevant if you have an antibiotic resistant strain of E. coli blooming in your intestine following antibiotic treatment/some other disruption of your microbiota.
A gut bacterial amyloid promotes α-synuclein aggregation and motor impairment in mice https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7012599/