Phenotypic switching of gastrointestinal smooth muscle cells and the regulatory role of macrophages: a literature review.

BACKGROUND: Gastrointestinal motility disorders are closely associated with dysfunction of smooth muscle cells (SMCs), and phenotypic switching of SMCs serves as a critical pathological basis for this process. Under a chronic inflammatory microenvironment, SMCs can transform into a synthetic phenotype and contribute to complications such as intestinal fibrosis. Macrophages, as the predominant immune cell population in the gastrointestinal tract, have an unclear role in regulating the phenotypic switching of SMCs, and the underlying mechanisms remain poorly understood. FINDINGS: This article systematically reviews the regulatory mechanisms underlying gastrointestinal smooth muscle phenotypic switching, and highlights the potential role of macrophages in regulating gastrointestinal smooth muscle phenotypic switching and summarizes the underlying mechanisms, including inflammatory responses, microbial interactions, and neural regulation. CONCLUSIONS: The macrophage‑smooth muscle axis provides new perspectives for understanding the pathogenesis of inflammatory bowel disease (IBD) and may serve as a reference for exploring potential therapeutic strategies for gastrointestinal motility disorders.