Microbiome-Derived Prion-Like Proteins and Their Potential to Trigger Cognitive Dysfunction

Abstract

Our life is intricately connected to microorganisms through infection or symbiotic relationships. While the inter-species propagation of prion-like proteins is well-established, their presence in the microbiome and impact on the host remains largely unexplored. To address this, we conducted a systematic study integrating in silico, in vitro, and in vivo analyses, showing that 63% of the gastrointestinal tract microbiome encodes prion-like sequences. These sequences can form amyloid fibrils capable of interfering with the aggregation of the Amyloid-beta-peptide and promoting the aggregation and propagation of the Sup35 prion. Finally, when C. elegans were fed with bacteria expressing chimeras of our prion candidates, it resulted in the loss of sensory memory, reproducing the Alzheimer's model phenotype. In our model, memory impairment is linked to aggregate fragmentation and its susceptibility to degradation. Taken together, these findings show that the gut microbiota serves as a potential reservoir of prion-like sequences, supporting the idea that microbial products may influence the pathogenesis of neurodegenerative diseases.