Establishing Murine Intestinal Organoids to Study Nutrient- and Tastant-Evoked Gut Signaling

Background/Objectives: Numerous studies have investigated the responses of the gastrointestinal tract to tastants, particularly in specialized enteroendocrine and other chemosensory cells. However, many of these investigations used various taste stimuli often at high concentrations or relied on immortalized cell lines or heterogeneous cell populations, which can limit their physiological relevance and reproducibility. To establish a stable, physiologically representative model system for consistently investigating gut epithelial responses to tastants, our study developed 3D murine intestinal organoids (MIOs). Methods: Murine intestinal organoids were generated from isolated intestinal crypts and cultured under defined conditions to maintain epithelial differentiation. Organoids were stimulated with selected nutrients and tastants, and downstream signaling responses were assessed using hormone secretion assays. Results: The 3D MIO culture system was successfully established, providing a robust in vitro platform for studying extraoral bitter sensing and release of the enteroendocrine hormone cholecystokinin. Moreover, 5 mM denatonium benzoate and 30 mM L-glutamic acid specifically induced cholecystokinin secretion in MIOs, whereas other bitter or non-bitter stimuli did not. Conclusions: Murine intestinal organoids provide a stable model for studying nutrient- and tastant-evoked signaling in the gut. This approach enables precise investigation of underlying mechanisms and may advance our understanding of gut chemosensation and metabolic regulation.