Gut power: Modulation of human amyloid formation by amyloidogenic proteins in the gastrointestinal tract

Abstract

Protein assembly into amyloid fibers underlies many neurodegenerative disorders. In Parkinson's disease, amyloid formation of α-synuclein is linked to brain cell death. The gut–brain axis plays a key role in Parkinson's disease, and initial α-synuclein amyloid formation may occur distant from the brain. Because different amyloidogenic proteins can cross-seed, and α-synuclein is expressed outside the brain, amyloids present in the gut (from food products and secreted by microbiota) may modulate α-synuclein amyloid formation via direct interactions. I here describe existing such data that only began to appear in the literature in the last few years. The striking, but limited, data set—spanning from acceleration to inhibition—calls for additional investigations that may unravel disease mechanisms as well as new treatments.