Establishment of an Apical-Out Organoid Model for Directly Assessing the Function of Postbiotics

Abstract

In vitro organoids that mimic the physiological properties of in vivo organs based on threedimensional cell cultures overcome the limitations of two-dimensional culture systems. However, because the lumen of a typical intestinal organoid is internal, we used an apical-out intestinal organoid model in which the lumen that absorbs nutrients is outside to directly assess the function of postbiotics. A composite culture supernatant of Lactiplantibacillus plantarum KM2 and Bacillus velezensis KMU01 was used as a postbiotic treatment. Expression of COX-2 decreased in apical-out organoids co-treated with a lipopolysaccharide (LPS) and postbiotics. Expression of tight-junction markers such as ZO-1, claudin, and Occludin increased, and expression of mitochondrial homeostasis factors such as PINK1, parkin, and PGC1a also increased. As a result, small and large intestine organoids treated with postbiotics protected tight junctions from LPS-induced damage and maintained mitochondrial homeostasis through mitophagy and mitochondrial biogenesis. This suggests that an apical-out intestinal organoid model can confirm the function of food ingredients.