Organoids for evaluating chronobiotics and functional foods

The intestinal epithelium functions as a peripheral circadian oscillator that regulates nutrient absorption, barrier integrity, and immune signaling across a 24-hour cycle. Chronic circadian disruption has been implicated in metabolic disease, prompting the emergence of chrono-nutrition as a framework recognizing that the bioactivity of food-derived compounds depends substantially on the circadian phase at the time of exposure. Chronobiotics, including dietary polyphenols, resistant starch-derived short-chain fatty acids, and postbiotics, modulate circadian amplitude and phase through epigenetic and microbiota-dependent mechanisms. Conventional two-dimensional models lack epithelial complexity and robust, tissue-like circadian rhythmicity, limiting temporally resolved and phase-accurate evaluation. Intestinal organoids derived from Lgr5+ stem cells or pluripotent stem cells overcome these limitations by harboring tissue-autonomous circadian clocks and supporting synchronized chronobiotic assessment through PER2::LUC bioluminescence recording and timed compound exposure. This review examines organoid-based evaluation of chronobiotics and functional foods across four functional domains: digestive stability, epithelial barrier function, microbiome interaction, and time-dependent efficacy. Technical and regulatory challenges associated with establishing organoids as a standardized platform for evidence-based functional food development are also discussed.