ID: hypothesis-h-7bb47d7a
Hypothesis

Bacterial Enzyme-Mediated Dopamine Precursor Synthesis

Engineered probiotic bacteria expressing tyrosine hydroxylase and aromatic L-amino acid decarboxylase could produce L-DOPA locally in the gut, providing sustained dopamine precursor delivery while bypassing hepatic metabolism and reducin.
🧬 TH, AADC🩺 neurodegeneration🎯 Composite 38%💱 $0.44▼25.1%archived
EvidencePending (0%)📖 23 cit🗣 1 debates 5 support 2 oppose
✓ All Quality Gates Passed
Mechanistic 0.30 (15%) Evidence 0.20 (15%) Novelty 0.90 (12%) Feasibility 0.10 (12%) Impact 0.40 (12%) Druggability 0.20 (10%) Safety 0.20 (8%) Competition 0.30 (6%) Data Avail. 0.20 (5%) Reproducible 0.10 (5%) KG Connect 0.31 (8%) 0.384 composite

🧪 Overview

Engineered probiotic bacteria expressing tyrosine hydroxylase and aromatic L-amino acid decarboxylase could produce L-DOPA locally in the gut, providing sustained dopamine precursor delivery while bypassing hepatic metabolism and reducing motor fluctuations.

🧬 Mechanism

🧬 Curated Mechanism Pathway

Curated pathway from expert analysis

graph TD
    A["L-Tyrosine<br/>Substrate"] --> B["Tyrosine Hydroxylase<br/>(TH)"]
    C["Tetrahydrobiopterin<br/>(BH4)"] --> B
    D["O2 and Fe2+<br/>Cofactors"] --> B
    B --> E["L-DOPA<br/>Intermediate"]
    E --> F["Aromatic L-amino acid<br/>Decarboxylase (AADC)"]
    G["Pyridoxal 5'-phosphate<br/>(PLP)"] --> F
    F --> H["Dopamine<br/>Product"]
    I["GTP Cyclohydrolase I<br/>(GTPCH1)"] --> J["BH4 Biosynthesis<br/>Pathway"]
    K["6-pyruvoyl-tetrahydropterin<br/>Synthase (PTPS)"] --> J
    J --> C
    L["Engineered Probiotic<br/>Bacteria"] --> B
    L --> F
    L --> I
    L --> K
    H --> M["Striatal Dopamine<br/>Restoration"]
    M --> N["Improved Motor<br/>Function"]
    O["Neurodegeneration<br/>Process"] --> P["Dopamine Depletion"]
    P --> Q["Motor Dysfunction<br/>Symptoms"]

    classDef normal fill:#4fc3f7,color:#0d0d1a
    classDef therapeutic fill:#81c784,color:#0d0d1a
    classDef pathology fill:#ef5350,color:#0d0d1a
    classDef outcome fill:#ffd54f,color:#0d0d1a
    classDef molecular fill:#ce93d8,color:#0d0d1a

    class A,C,D,G normal
    class B,F,I,J,K,L therapeutic
    class O,P,Q pathology
    class M,N outcome
    class E,H molecular

⚖️ Evidence

⚖️ Evidence Matrix5 supports2 contradicts
Supports
Mild/moderate phenotypes in AADC deficiency: Focus on the aromatic amino acid decarboxylase protein.
J Inherit Metab Dis2025PMID:39166734medium
Supports
Compound Heterozygosis in AADC Deficiency and Its Complex Phenotype in Terms of AADC Protein Population.
Int J Mol Sci2022PMID:36232540medium
Supports
Gene therapy for aromatic L-amino acid decarboxylase deficiency by MR-guided direct delivery of AAV2-AADC to midbrain dopaminergic neurons.
Nat Commun2021PMID:34253733medium
Supports
A review of aromatic l-amino acid decarboxylase (AADC) deficiency in Taiwan.
Am J Med Genet C Semin Med Genet2019PMID:30614627medium
Supports
Blood, urine and cerebrospinal fluid analysis in TH and AADC deficiency and the effect of treatment.
Mol Genet Metab Rep2021PMID:33996491medium
Contradicts
Gut bacteria can metabolize levodopa through an interspecies pathway, implying engineered gut catecholamine precursor production may be degraded or pharmacokinetically unstable.
Science2019PMID:31196984medium
Contradicts
Gut bacterial tyrosine decarboxylases restrict levodopa levels, directly challenging assumptions that intestinal bacterial dopamine-precursor handling is reliably beneficial.
Nat Commun2019PMID:30659181medium
📖 Linked Papers (19)Export BibTeX ↗
Fig. 1
Fig. 1
Schematics of single-cell spatial reconstruction by CSOmap. a CSOmap takes the gene-by-cell expression matrix generated by scRNA-seq and the known ligand-recep...
Fig. 2
Fig. 2
The exocrine and endocrine compartments of pancreas can be recapitulated by ligand-receptor based inference with CSOmap. a The 3D visualization of CSOmap predi...
Figure 1
Figure 1
( A ) Ribbon diagram of the heterotypic human I-BABP:GCDA:GCA complex determined by solution NMR (PDB entry 2MM3 6 ). Bound bile salts are shown in a ball-and-s...
Figure 2
Figure 2
ITC analysis of the pH-dependence of bile salt binding to human I-BABP. Injection profiles for ( A ) GCA and ( B ) GCDA at pH = 7.2. The discontinuity at an x a...
Antiparkinson prodrugs.
Molecules (Basel, Switzerland) (2008) · PubMed:18259129 ↗
24 figures
Scheme 1
Scheme 1
Dopamine biosynthesis.
Figure 1
Figure 1
No caption available
Figures
Figures
Figures available at source paper (no open-access XML found).
Figures
Figures
Figures available at source paper (no open-access XML found).
Neurosurgical gene therapy for central nervous system diseases.
Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics (2024) · PubMed:39191071 ↗
No figures
Long-term efficacy and safety of eladocagene exuparvovec in patients with AADC deficiency.
Molecular therapy : the journal of the American Society of Gene Therapy (2022) · PubMed:34763085 ↗
No figures
Current Clinical Applications of In Vivo Gene Therapy with AAVs.
Molecular therapy : the journal of the American Society of Gene Therapy (2021) · PubMed:33309881 ↗
No figures
📙 Related Wiki Pages (15)

🏥 Translation

🧬 3D Protein Structure — TH

No curated PDB or AlphaFold mapping for TH yet. Search RCSB →

🧠 GTEx v10 Brain ExpressionJSON

Median TPM across 13 brain regions for TH, AADC from GTEx v10.

Substantia nigra36.9 Hypothalamus15.9 Caudate basal ganglia5.3 Nucleus accumbens basal ganglia3.9 Hippocampus0.9 Putamen basal ganglia0.8 Anterior cingulate cortex BA240.8 Cortex0.6 Frontal Cortex BA90.5 Amygdala0.5 Spinal cord cervical c-10.1 Cerebellum0.0 Cerebellar Hemisphere0.0median TPM (GTEx v10)

💉 Clinical Trials (6)Relevance: 45%

0
Active
0
Completed
328
Total Enrolled
PHASE1
Highest Phase
COMPLETED·NCT03317431 · Xinhua Hospital, Shanghai Jiao Tong University School of Medicine
46 enrolled · 2017-03-20 · → 2017-10-22
Dopamine(DA) is a common neurotransmitter that has been known to regulate behavior, movement, cardiovascular,endocrine and gastrointestinal functions, but also functions as an important molecule engag
Acute Lung Injury
mechanical ventilation
RECRUITING·NCT04220190 · Rapa Therapeutics LLC
41 enrolled · 2025-01-02 · → 2026-07-01
RAPA-501-ALS is a phase 2/3 expansion cohort study of RAPA-501 autologous hybrid TREG/Th2 cells in patients living with amyotrophic lateral sclerosis (pwALS).
Amyotrophic Lateral Sclerosis
RAPA-501 Autologous T stem cells
COMPLETED·NCT03955380 · Prof. Dr. Dieter Willbold
24 enrolled · 2018-12-12 · → 2019-04-03
This is a single-center multiple-ascending-dose clinical trial assessing the safety and tolerability of oral dosing of Contraloid acetate in healthy volunteers. The study drug Contraloid (alias RD2, a
Alzheimer Dementia Alzheimer Disease
Contraloid
UNKNOWN·NCT04820881 · Washington D.C. Veterans Affairs Medical Center
60 enrolled · 2021-10-01 · → 2024-09
This grant award entitled, "Cerebrovascular Reactivity and Oxygen Metabolism as Markers for Neurodegeneration after Traumatic Brain Injury" (hereafter, "Neurovascular Study"), aims to determine if neu
Neurodegenerative Diseases
NOT_YET_RECRUITING·NCT07212088 · iCamuno Biotherapeutics Ltd.
12 enrolled · 2026-02-28 · → 2027-12-15
Parkinson's disease is a progressive neurodegenerative disorder characterized by high morbidity due to the limited regenerative capacity of dopaminergic neurons in the brain. Current drug treatments p
Parkinson Disease
ALC01 therapy
COMPLETED·NCT02405182 · University of Alberta
145 enrolled · 2014-09 · → 2019-03
Amyotrophic lateral sclerosis (ALS) is a disabling and rapidly progressive neurodegenerative disorder. There is no treatment that significantly slows progression. Increasing age is an important risk f
Amyotrophic Lateral Sclerosis ALS Motor Neuron Diseases
Magnetic Resonance Imaging

No curated ClinVar variants loaded for this hypothesis.

Run scripts/backfill_clinvar_variants.py to fetch P/LP/VUS variants.

🔍 Search ClinVar for TH, AADC →

No DepMap CRISPR Chronos data found for TH, AADC.

Run python3 scripts/backfill_hypothesis_depmap.py to populate.

💰 Estimated Development
Cost
$0
Timeline
3.5 years

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📊 Market Indicators

7d Trend
Stable
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Volatility
High
0.0879
Events (7d)
2
Price History
▼25.1%

💾 Resource Usage

LLM Tokens
34,972
$0.2158
Total Cost
$0.2158

🔮 Predictions

🔎 Predictions vs Observations3 predictions · 0 with recorded observations
PredictionPredictedObservedStatusConf
If hypothesis is true, intervention prioritize patients with demonstrated L-DOPA responsiveness but emerging motor fluctuations, as this population represents the optimal risk-benefit profile for initprioritize patients with demonstrated L-DOPA responsiveness but emerging motor fluctuations, as this population represents the optimal risk-benefit profile for — no observation —pending0.20
If hypothesis is true, intervention effectively restore dopaminergic signaling in 6-OHDA-treated neuronal cultures, with 70-80% recovery of tyrosine hydroxylase-positive cell populationseffectively restore dopaminergic signaling in 6-OHDA-treated neuronal cultures, with 70-80% recovery of tyrosine hydroxylase-positive cell populations— no observation —pending0.20
If hypothesis is true, intervention inhibit bacterial growth through feedback mechanismsinhibit bacterial growth through feedback mechanisms— no observation —pending0.20
🔮 Falsifiable Predictions (3)
pendingconf 20%
If hypothesis is true, intervention inhibit bacterial growth through feedback mechanisms
Predicted outcome: inhibit bacterial growth through feedback mechanisms
Falsification: Intervention fails to inhibit bacterial growth through feedback mechanisms
pendingconf 20%
If hypothesis is true, intervention effectively restore dopaminergic signaling in 6-OHDA-treated neuronal cultures, with 70-80% recovery of tyrosine hydroxylase-positive cell populations
Predicted outcome: effectively restore dopaminergic signaling in 6-OHDA-treated neuronal cultures, with 70-80% recovery of tyrosine hydroxylase-positive cell populations
Falsification: Intervention fails to effectively restore dopaminergic signaling in 6-OHDA-treated neuronal cultures, with 70-80% recovery of tyrosine hydroxylase-positive cell populations
pendingconf 20%
If hypothesis is true, intervention prioritize patients with demonstrated L-DOPA responsiveness but emerging motor fluctuations, as this population represents the optimal risk-benefit profile for initial studies
Predicted outcome: prioritize patients with demonstrated L-DOPA responsiveness but emerging motor fluctuations, as this population represents the optimal risk-benefit pr
Falsification: Intervention fails to prioritize patients with demonstrated L-DOPA responsiveness but emerging motor fluctuations, as this population represents the optimal risk-benefit profile for initial studies
Related Entities
Metadata
statusproposed
_schema_version1
hypothesis_typeNone
📊 Evidence Profile Foundational
Evidence Balance
+0%
Certainty
100%
Debates
0
Incoming
5420
Outgoing
3914
0 supporting 0 contradicting 0 neutral
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