graph TD
    A["Commensal Bacteria<br/>Akkermansia and Lactobacillus"] --> B["SCFA Production<br/>Butyrate and Propionate"]
    A --> C["Specialized Metabolites<br/>Indole-3-propionic acid and GABA precursors"]
    B --> D["Intestinal Epithelium<br/>Metabolite Transport"]
    C --> D
    D --> E["Enteroendocrine L-cells<br/>Activation"]
    E --> F["GLP-1 Release<br/>Incretin Hormone"]
    F --> G["Vagal Afferent GLP1R<br/>Receptor Binding"]
    G --> H["cAMP Signaling<br/>G-protein Activation"]
    H --> I["Vagal Nerve<br/>Signal Transmission"]
    I --> J["Brainstem Integration<br/>Nucleus Tractus Solitarius"]
    J --> K["Neuroinflammation Reduction<br/>Anti-inflammatory Response"]
    J --> L["Neuroprotection<br/>Synaptic Plasticity"]
    K --> M["Disease Endpoint<br/>Reduced Neurodegeneration"]
    L --> M
    N["Therapeutic Intervention<br/>Probiotic Supplementation"] --> A
    O["GLP-1 Receptor Agonists<br/>Pharmacological Target"] --> G
    
    style N fill:#e1f5fe,color:#0d0d1a
    style O fill:#e1f5fe,color:#0d0d1a
    style M fill:#ffebee,color:#0d0d1a