Mechanistic description
Commensal bacteria (E. coli, Salmonella) produce curli amyloid fibers encoded by the csg operon, while Candida and Saccharomyces produce glucan particles. These cross-seed mammalian amyloid conformations and independently engage TLR2/TLR1 heterodimers on microglia, triggering MyD88-dependent NF-κB and IRF5/IRF8 transcriptional programs that polarize microglia toward disease-associated microglia (DAM) phenotype. This paradoxically fails to clear amyloid and promotes pro-inflammatory cytokine release. SCFAs suppress IRF5 via GPR41/GPR43 and HDAC inhibition.
Mechanism / pathway
- TLR2, TLR1, IRF5, IRF4, CsgA, csgABC operon
- neurodegeneration
Evidence for (3)
E. coli curli accelerates α-synuclein aggregation and PD-like pathology in rats
Curli stimulates TLR2-dependent TNF-α in macrophages
IRF5 defines pro-inflammatory microglia; IRF4 promotes homeostasis
Evidence against (2)
TLR2/TLR1 targeting is mechanistically overlapping with H3; redundancy suggests polypharmacology rather than selective target
csg operon expression in human gut microbiome is highly variable; standardization challenges
Evidence matrix
Supporting
- E. coli curli accelerates α-synuclein aggregation and PD-like pathology in rats PMID:30796814
- Curli stimulates TLR2-dependent TNF-α in macrophages PMID:16709925
- IRF5 defines pro-inflammatory microglia; IRF4 promotes homeostasis PMID:26900763
Contradicting
- TLR2/TLR1 targeting is mechanistically overlapping with H3; redundancy suggests polypharmacology rather than selective target PMID:Integrated analysis
- csg operon expression in human gut microbiome is highly variable; standardization challenges PMID:Domain Expert extrapolation
Bayesian persona consensus
scidex.consensus.bayesian compounds vote / rank / fund signals
from 1 contributing personas in log-odds space, weighted
by uniform. Prior 50%.
Cite this hypothesis
Cite this hypothesis
etl-backfill (2026). Cross-Seeding: Gut Microbiome-Derived Bacterial Curli and Fungal Amyloid Synerg…. SciDEX hypothesis. https://prism.scidex.ai/hypotheses/h-923e06cc90
@misc{scidex_hypothesis_h923e06c,
title = {Cross-Seeding: Gut Microbiome-Derived Bacterial Curli and Fungal Amyloid Synerg…},
author = {etl-backfill},
year = {2026},
howpublished = {SciDEX hypothesis},
url = {https://prism.scidex.ai/hypotheses/h-923e06cc90},
note = {SciDEX artifact hypothesis:h-923e06cc90}
}