ID: 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.
EvidencePending (0%)📖 23 cit🗣 1 debates✓ 5 support✗ 2 oppose
✓ All Quality Gates Passed
🧪 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.
Supports
Compound Heterozygosis in AADC Deficiency and Its Complex Phenotype in Terms of AADC Protein Population.
Supports
Gene therapy for aromatic L-amino acid decarboxylase deficiency by MR-guided direct delivery of AAV2-AADC to midbrain dopaminergic neurons.
Supports
A review of aromatic l-amino acid decarboxylase (AADC) deficiency in Taiwan.
Supports
Blood, urine and cerebrospinal fluid analysis in TH and AADC deficiency and the effect of treatment.
Contradicts
Gut bacteria can metabolize levodopa through an interspecies pathway, implying engineered gut catecholamine precursor production may be degraded or pharmacokinetically unstable.
Contradicts
Gut bacterial tyrosine decarboxylases restrict levodopa levels, directly challenging assumptions that intestinal bacterial dopamine-precursor handling is reliably beneficial.
📖 Linked Papers (19)Export BibTeX ↗
Reconstruction of cell spatial organization from single-cell RNA sequencing data based on ligand-receptor mediated self-assembly.
Cell research (2020) · PubMed:32541867 ↗
8 figures

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
The exocrine and endocrine compartments of pancreas can be recapitulated by ligand-receptor based inference with CSOmap. a The 3D visualization of CSOmap predi...
Ligand entry in human ileal bile acid-binding protein is mediated by histidine protonation.
Scientific reports (2019) · PubMed:30886237 ↗
10 figures

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
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...
Tyrosine hydroxylase (TH), its cofactor tetrahydrobiopterin (BH4), other catecholamine-related enzymes, and their human genes in relation to the drug and gene therapies of Parkinson's disease (PD): historical overview and future prospects.
Journal of neural transmission (Vienna, Austria : 1996) (2016) · PubMed:27491309 ↗
1 figure
Figures
Figures available at source paper (no open-access XML found).
Antiparkinson prodrugs.
Molecules (Basel, Switzerland) (2008) · PubMed:18259129 ↗
24 figures

Scheme 1
Dopamine biosynthesis.

Figure 1
No caption available
Altered fractionation: a fractional benefit?
The Lancet (2006) · PubMed:16950339 ↗
1 figure
Figures
Figures available at source paper (no open-access XML found).
Assessment of neuroimaging techniques as biomarkers of the progression of Parkinson's disease.
Experimental neurology (2003) · PubMed:14597329 ↗
1 figure
Figures
Figures available at source paper (no open-access XML found).
Gene therapy for Parkinson's disease: current landscape, translational challenges, and future directions.
Expert review of neurotherapeutics (2026) · PubMed:41837837 ↗
No figures
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
Targeting autophagy using small-molecule compounds to improve potential therapy of Parkinson's disease.
Acta pharmaceutica Sinica. B (2021) · PubMed:34729301 ↗
No figures
Gene therapy restores dopamine transporter expression and ameliorates pathology in iPSC and mouse models of infantile parkinsonism.
Science translational medicine (2021) · PubMed:34011628 ↗
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)
Glymphatic Waste Clearance Therapy for PtherapeuticMedial HypothalamuscellAxonal Transport Dysfunction Hypothesis hypothesisParacentral Thalamic NucleuscellSection 200: Epigenetic and Chromatin ThtherapeuticGSK3 Inhibitor TherapytherapeuticMETTL14 Protein (m6A Methyltransferase SproteinCNS Drug Delivery MethodsmechanismMathias Juckerresearcher4R Tauopathy Differential BiomarkersbiomarkerPSP and Idiopathic Normal Pressure HydrodiseaseEphB Receptor Modulator TherapytherapeuticInnate Immune Signaling Pathways in Alzhmechanismwhite-matter-lesion-pathwaymechanismSynapse-Resilience Circuit: BDNF Therapyidea
🏥 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.
💉 Clinical Trials (6)Relevance: 45%
0
Active
Active
0
Completed
Completed
328
Total Enrolled
Total Enrolled
PHASE1
Highest Phase
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
RAPA-501 Therapy for ALSPHASE2
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
Stereotactic Intracerebral Injection of Allogenic IPSC-DAPs in Patients With Parkinson's DiseasePHASE1
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.
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
🏆 Tournament
🏆 Arenas / Elo
No arena matches recorded yet. Browse Arenas →
📊 Market Indicators
7d Trend
↔
Stable
7d Momentum
▲ 0.6%
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
| Prediction | Predicted | Observed | Status | Conf |
|---|---|---|---|---|
| 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 init | prioritize patients with demonstrated L-DOPA responsiveness but emerging motor fluctuations, as this population represents the optimal risk-benefit profile for | — no observation — | pending | 0.20 |
| 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 | effectively restore dopaminergic signaling in 6-OHDA-treated neuronal cultures, with 70-80% recovery of tyrosine hydroxylase-positive cell populations | — no observation — | pending | 0.20 |
| If hypothesis is true, intervention inhibit bacterial growth through feedback mechanisms | inhibit bacterial growth through feedback mechanisms | — no observation — | pending | 0.20 |
🔮 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
▸Metadatasource: v1_phase_c_backfill · origin_type: gap_debate
| source | v1_phase_c_backfill |
| origin_type | gap_debate |
| _schema_version | 1 |
📊 Evidence Profile
Evidence Balance
+0%
Certainty
0%
Debates
0
Incoming
0
Outgoing
0
0 supporting
0 contradicting
0 neutral
Public annotations (0)Annotate on Hypothes.is →
No public annotations yet.