Abstract
The gastrointestinal (GI) tract constitutes a sophisticated system integral to digestion, nutrient absorption, and overall health, with its functionality predominantly hinging on the distinctive properties of diverse stem cell types. This review systematically investigates the pivotal roles of stem cells across the esophagus, stomach, small intestine, and colon, emphasizing their crucial contributions to tissue homeostasis, repair mechanisms, and regeneration. Each segment of the GI tract is characterized by specialized stem cell populations that exhibit distinct functional attributes, highlighting the necessity for tailored therapeutic approaches in the management of gastrointestinal disorders.Emerging research has shed light on the functional heterogeneity of GI stem cells, with ISCs in the small intestine displaying remarkable turnover rates and regenerative potential, whereas colonic stem cells (CSCs) are essential for the preservation of the colonic epithelial barrier. The intricate interplay between stem cells and their microenvironment-or niche-is fundamentally important for their functionality, with critical signaling pathways such as Wnt and Notch exerting substantial influence over stem cell behavior. The advent of organoid models derived from GI stem cells offers promising avenues for elucidating disease mechanisms and for the preclinical testing of novel therapeutic interventions.Despite notable advancements in foundational research on GI stem cells, the translation of these scientific discoveries into clinical practice remains limited. As of 2025, Japan's clinical GI disease guidelines do not endorse any stem cell-based therapies, underscoring the existing disconnect between research findings and clinical application. This scenario accentuates the urgent need for sustained efforts to bridge this divide and to cultivate innovative strategies that synergize stem cell technology with conventional treatment modalities.Future investigations should be directed toward unraveling the mechanisms that underpin stem cell dysfunction in various gastrointestinal pathologies, as well as exploring combination therapies that harness the regenerative capacities of stem cells in conjunction with immunomodulatory treatments. By fostering collaborative endeavors between basic researchers and clinical practitioners, we can deepen our understanding of GI stem cells and facilitate the translation of this knowledge into effective therapeutic interventions, ultimately enhancing patient outcomes in gastrointestinal diseases.