Innate immune functions of bitter taste receptors across physiological systems

Abstract

Background: Bitter taste receptors (TAS2Rs) were initially regarded as sensors for potentially toxic substances, but accumulating evidence indicates that they also play an important role in the regulation of innate immunity. The aim of this study is to summarize the major immunological functions of bitter taste receptors and to clarify their relevance across different physiological systems.

Main body: Current studies suggest that bitter taste receptors contribute to microbial sensing and immune defense in the respiratory tract, maintain microbial homeostasis and antimicrobial activity in the digestive system, and participate in inflammatory regulation and local immune balance in the musculoskeletal and reproductive systems. In addition, they are involved in immune-related processes in the nervous, circulatory, endocrine, and urinary systems.

Conclusions: Collectively, these findings indicate that bitter taste receptors act as widely distributed immune-sensing molecules that link environmental stimuli to innate immune responses, providing a broader framework for understanding multisystem immune defense mechanisms.

Keywords: Bitter taste receptors; Immune regulation; Inflammation; Innate immunity; TAS2Rs.