Abstract
The in vitro differentiation of pluripotent stem cells into human intestinal organoids (HIOs) has served as a powerful means for creating complex three-dimensional intestinal structures. Owing to their diverse cell populations, transplantation into an animal host is supported with this system and allows the temporal formation of fully laminated structures, including crypt-villus architecture and smooth muscle layers that resemble native human intestine. Although the endpoint of HIO engraftment has been well described, here we aim to elucidate the developmental stages of HIO engraftment and establish whether it parallels fetal human intestinal development. We analyzed a time course of transplanted HIOs histologically at 2, 4, 6 and 8 weeks post-transplantation, and demonstrated that HIO maturation closely resembles key stages of fetal human intestinal development. We also utilized single-nuclear RNA sequencing to determine and track the emergence of distinct cell populations over time, and validated our transcriptomic data through in situ protein expression. These observations suggest that transplanted HIOs do indeed recapitulate early intestinal development, solidifying their value as a human intestinal model system.