Rebalancing the inflammatory niche in allergic rhinitis "

Area of Science:

• Immunology
• Microbiology
• Pharmacology

Background:

• Allergic rhinitis (AR) pathogenesis involves complex interactions between resident microbiota, microbe-derived molecules, and group 2 innate lymphoid cells (ILC2s).
• Traditional Chinese Medicine (TCM) has shown potential in modulating immune responses, but its precise mechanisms in AR require elucidation.

Purpose of the Study:

• To review the signaling axes through which TCM influences the microbiota-ILC2 network in AR.
• To explore the role of microbial metabolites, including short-chain fatty acids (SCFAs), bile acids, and tryptophan metabolites, in TCM's therapeutic effects on AR.

Main Methods:

• Review of preclinical and emerging clinical data on TCM formulas and phytochemicals.
• Analysis of molecular mediators involved in TCM-driven microbiome and metabolome changes.
• Focus on signaling pathways such as HDAC inhibition, SCFA receptor signaling, FXR/TGR5, and AhR activation.

Main Results:

• TCM interventions are associated with remodeling of gut and airway microbiota, increasing beneficial metabolites like SCFAs, bile acids, and indoles.
• Selected TCMs demonstrate direct attenuation of epithelial alarmin signaling (TSLP/IL-33) in preclinical models.
• Specific molecular mediators (e.g., HDAC, GPR41/43, FXR/TGR5, AhR) are linked to TCM actions on the microbiota-ILC2 axis.

Conclusions:

• TCM offers mechanism-based strategies to suppress ILC2 activation and restore mucosal homeostasis in AR.
• Further mechanistic clinical investigations are required to establish causality and optimize TCM-based AR therapies.