Eosinophil adaptation in the intestine: microenvironmental cues and regulatory roles

Eosinophils are granulocytes that undergo extensive transcriptional and functional remodeling as they adapt to tissue-specific microenvironments, enabling them to perform context-dependent roles in both homeostasis and disease. The intestine, one of the most eosinophil-rich organs, exhibits profound spatial, temporal, and physiological heterogeneity that governs eosinophil adaptation. In this review, we present an integrative spatiotemporal and physiological framework that synthesizes current insights into how intestinal microenvironmental cues shape eosinophil identity and function. We first summarize regional specialization of eosinophils across the intestinal tract, followed by a systematic overview of the key factors that imprint eosinophil phenotype. We next discuss how these niche-driven adaptations enable eosinophils to regulate epithelial homeostasis, microbiota, and context-specific immune responses. We further review emerging clinical findings to highlight conserved and divergent aspects of eosinophil adaptation across intestinal diseases. A deeper understanding of the mechanisms underlying eosinophil adaptation in the gut may pave the way for targeted therapeutic strategies in intestinal health and disease.