Gut microbiome-derived short-chain fatty acids (SCFAs), particularly butyrate and propionate, modulate microglial activation and neuroinflammation in Alzheimer's disease. Impaired SCFA signaling represents a modifiable therapeutic target.
Objective: Establish correlation between peripheral SCFA levels and CNS inflammation markers
Design: Cross-sectional study
Power Analysis: N=50 per group provides 80% power to detect d=0.5 at α=0.05
Timeline: 18 months
Cost: $2.8M (see breakdown below)
Cost Breakdown:
| Item | Cost (USD) |
|---|---|
| Participant recruitment & retention | $400,000 |
| SCFA GC-MS assays | $150,000 |
| CSF collection & cytokine assays | $300,000 |
| Microbiome sequencing | $200,000 |
| PET imaging (amyloid, tau, PBR28) | $1,200,000 |
| Clinical assessments | $250,000 |
| Data management | $200,000 |
| Statistical analysis | $150,000 |
| Total | $2,850,000 |
Expected outcome if hypothesis true: Negative correlation between SCFAs and CSF inflammatory markers; SCFA levels predict neuroinflammation PET signal
Objective: Test whether increasing butyrate reduces neuroinflammation
Design: Randomized, placebo-controlled trial
Power Analysis: N=60 per arm provides 80% power to detect 25% reduction in IL-1β at α=0.05
Timeline: 36 months (12 month treatment + 24 month follow-up)
Cost: $5.2M (see breakdown below)
Cost Breakdown:
| Item | Cost (USD) |
|---|---|
| Study drug (sodium butyrate) | $180,000 |
| Participant recruitment | $500,000 |
| MRI scans (baseline, 6mo, 12mo) | $360,000 |
| PET scans (baseline, 12mo) | $720,000 |
| CSF collection & assays | $480,000 |
| Plasma biomarkers | $240,000 |
| Cognitive testing (Cogstate) | $300,000 |
| Clinical coordination | $600,000 |
| Data management | $400,000 |
| Statistical analysis | $250,000 |
| Regulatory & compliance | $170,000 |
| Total | $5,200,000 |
Key controls:
Expected outcome if hypothesis true: Reduced CSF inflammatory markers, slowed biomarker progression
Objective: Determine how SCFAs reach the CNS
Design: Mouse model + in vitro
Power Analysis: N=10 mice per group for animal studies
Timeline: 24 months
Cost: $1.1M (see breakdown below)
Cost Breakdown:
| Item | Cost (USD) |
|---|---|
| Mouse colony & maintenance | $150,000 |
| Radioisotope studies | $200,000 |
| In vitro BBB assays | $100,000 |
| PET synthesis (11C-butyrate) | $250,000 |
| Human PET studies (5 subjects) | $150,000 |
| Data analysis | $100,000 |
| Personnel | $150,000 |
| Total | $1,100,000 |
Expected outcome: SCFAs cross BBB via carrier-mediated transport, not passive diffusion
| Study | Duration | Cost |
|---|---|---|
| Study 1: Cross-sectional | 18 months | $2.85M |
| Study 2: RCT | 36 months | $5.20M |
| Study 3: Mechanistic | 24 months | $1.10M |
| Total | 48 months | $9.15M |
Add 15% contingency: $1.37M
Grand Total: ~$10.5M
| Dimension | Score | Rationale |
|---|---|---|
| Scientific Value | 9 | Addresses fundamental gut-brain mechanism in AD |
| Feasibility | 7 | Multi-study program requires strong coordination |
| Novelty | 9 | First integrated SCFA-BBB-neuroinflammation study |
| Disease Impact | 9 | Modifiable therapeutic target with dietary intervention |
| Reach | 8 | Applicable to AD, PD, ALS, and other neurodegenerative conditions |
| Cost Efficiency | 7 | $10.5M for comprehensive 3-study program is reasonable |
| Time Efficiency | 5 | 48 months is lengthy but necessary for rigor |
| Evidence Base | 5 | Strong preclinical, weak clinical - addresses this gap |
| Addresses Uncertainty | 10 | Tests causality, mechanism, and therapy simultaneously |
| Translation Potential | 9 | Dietary intervention, supplements are highly translatable |
Total Score: 68/100 (Average: 6.8/10)
Reviewed: 2026-03-21