Modulating Th17/Treg Balance in Alzheimer's Disease: Therapeutic Insights from Natural Compounds and Immunometabolism

Background/Objectives: Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive cognitive decline and chronic neuroinflammation. Increasing evidence suggests that the imbalance between pro-inflammatory Th17 cells and anti-inflammatory regulatory T (Treg) cells plays a critical role in AD pathogenesis. However, a comprehensive synthesis of how natural compounds modulate Th17/Treg balance in AD remains lacking. This review aims to summarize current preclinical evidence on Th17/Treg dysregulation and evaluate the immunomodulatory potential of natural compounds in AD. Methods: This review focuses on preclinical evidence derived from experimental AD models and related inflammatory models to evaluate how natural compounds modulate Th17/Treg balance, neuroinflammation, and cognitive function, with an emphasis on underlying molecular and immunometabolic mechanisms. Results: Th17/Treg imbalance contributes significantly to AD-associated neuroinflammation and disease progression. Representative natural compounds, including paeoniflorin, quercetin, and ganoderic acid A, have demonstrated the ability to rebalance Th17/Treg responses, suppress neuroinflammation, and improve neuronal survival in experimental models. These compounds are highlighted due to their relatively stronger evidence in AD-related models and more clearly defined immunomodulatory mechanisms. These effects are partially mediated through modulation of key signaling pathways and immunometabolic reprogramming. Conclusions: Targeting Th17/Treg balance with natural compounds represents a promising multi-target immunomodulatory strategy for AD. However, most current evidence is derived from preclinical or non-AD models, and clinical validation remains limited. Future studies should prioritize AD-specific models and translational research to evaluate therapeutic potential in humans.