Transplanted human intestinal organoids: A resource for modeling human intestinal development.

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. Due to their diverse cell populations, transplantation into an animal host is supported with this system and allows for the temporal formation of fully laminated structures, including crypt-villus architecture and smooth muscle layers which resemble native human intestine. While the endpoint of HIO engraftment has been well described, here, we aim to elucidate the developmental stages of HIO engraftment and establish if it parallels fetal human intestinal development. We analyzed a timecourse of transplanted HIOs histologically at two, four, six and eight 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 indeed recapitulate early intestinal development, solidifying their value as a human intestinal model system.