Co-aggregation of pre-conditioned cell populations drives controlled lineage bias and formation of gut tube-like structures in human stem cell-based embryo models

Human stem cell-based embryo models (hSCBEMs) provide a powerful platform for investigating post-implantation human embryo development but are frequently hindered by variability in growth and morphogenesis as well as incomplete lineage representations. Here, we present a modular hSCBEM aggregation approach based on co-aggregation of differentially pre-conditioned, human pluripotent stem cell derived cells pools. Using this strategy, we generated hSCBEM with consistent morphotypes that targets robust morphogenesis of gut tube-like structures in combination with mesodermal lineages. Our findings demonstrate that co-aggregating defined cellular heterogeneity represents a versatile approach to specifically guide self-organization in hSCBEMs while improving reproducibility and developmental fidelity. The approach provides a robust platform for supervised morphogenesis in hSCBEMs.