Mechanistic description
In Parkinson’s disease, elevated H2S-producing Desulfovibrio species and depleted butyrate-producing Faecalibacterium prausnitzii create a metabolite imbalance that simultaneously disrupts gut barrier integrity and increases systemic LPS translocation. The resulting TLR4 activation on enteric neurons triggers NF-κB-mediated neuroinflammation, promoting local alpha-synuclein misfoldling and aggregation. This enteric pathology then propagates bidirectionally along the vagus nerve to the dorsal motor nucleus and from autonomic ganglia to peripheral neurons, representing the gut-first progression of PD. Fecal transplant to germ-free α-synuclein transgenic mice will test whether disease-specific microbial communities are sufficient to induce enteric protein aggregation and whether Desulfovibrio colonization alone reproduces the pathological phenotype.
Mechanism / pathway
- SNCA
- Gut barrier dysfunction/TLR4 neuroinflammation
- Parkinson's disease
Evidence for (5)
Monogenic Parkinson's Disease: Genotype, Phenotype, Pathophysiology, and Genetic Testing.
SNCA REP1 and Parkinson's disease.
Parkinson's disease - genetic cause.
SNCA-AS1 in aging and Parkinson's disease.
Mitochondria and Parkinson's Disease: Clinical, Molecular, and Translational Aspects.
Evidence against (2)
Strain-specific effects of Desulfovibrio on neurodegeneration show that not all H2S-producing Desulfovibrio strains enhance alpha-synuclein aggregation equally; the variability in outcomes indicates that factors beyond H2S production (e.g. specific lipopolysaccharide structures) are responsible, challenging the H2S-centric mechanism
TLR4/NF-κB neuroinflammation from gut dysbiosis in Parkinson's is activated more potently by bacterial lipopolysaccharides than by H2S; the proposed H2S/butyrate balance as the primary TLR4 driver is not experimentally distinguished from co-occurring LPS-mediated activation in PD gut microbiome studies
Evidence matrix
Supporting
- Monogenic Parkinson's Disease: Genotype, Phenotype, Pathophysiology, and Genetic Testing. PMID:35328025 · 2022 · Genes (Basel)
- SNCA REP1 and Parkinson's disease. PMID:29859327 · 2018 · Neurosci Lett
- Parkinson's disease - genetic cause. PMID:37366140 · 2023 · Curr Opin Neurol
- SNCA-AS1 in aging and Parkinson's disease. PMID:35438650 · 2022 · Aging (Albany NY)
- Mitochondria and Parkinson's Disease: Clinical, Molecular, and Translational Aspects. PMID:33074190 · 2021 · J Parkinsons Dis
Contradicting
- Strain-specific effects of Desulfovibrio on neurodegeneration show that not all H2S-producing Desulfovibrio strains enhance alpha-synuclein aggregation equally; the variability in outcomes indicates that factors beyond H2S production (e.g. specific lipopolysaccharide structures) are responsible, challenging the H2S-centric mechanism PMID:40790298 · 10.1038/s41598-025-96823-4
- TLR4/NF-κB neuroinflammation from gut dysbiosis in Parkinson's is activated more potently by bacterial lipopolysaccharides than by H2S; the proposed H2S/butyrate balance as the primary TLR4 driver is not experimentally distinguished from co-occurring LPS-mediated activation in PD gut microbiome studies PMID:41694373 · 10.3389/fnins.2026.1572943
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). H2S/butyrate imbalance drives enteric alpha-synuclein pathology via TLR4 signal…. SciDEX hypothesis. https://prism.scidex.ai/hypotheses/h-cc60dcd54d
@misc{scidex_hypothesis_hcc60dcd,
title = {H2S/butyrate imbalance drives enteric alpha-synuclein pathology via TLR4 signal…},
author = {etl-backfill},
year = {2026},
howpublished = {SciDEX hypothesis},
url = {https://prism.scidex.ai/hypotheses/h-cc60dcd54d},
note = {SciDEX artifact hypothesis:h-cc60dcd54d}
}