The present invention relates to an in vitro method of culturing a segmented filamentous bacterium strain, comprising co-culturing said segmented filamentous bacterium strain with a eukaryotic host cell, wherein the culture is performed at an O.sub.2 level inferior to 5% in a rich tissue culture liquid medium containing bacterial medium components including iron. The present invention also relates to methods for genetically modifying a segmented filamentous bacterium strain comprising a step a culturing the strain in vitro.

A cultured tissue, comprising: glandular cells; glandular cavities formed from the glandular cells; and ducts formed from epithelial cells, wherein the glandular cavities and the ducts are functionally connected ex vivo.

A population of enteroendocrine cells (EEC) is obtained from a mammalian post-natal cell population, such as a population including post-natal stem cells, by treating the population with a plurality of small molecules that upregulate ChgA and promote differentiation of the cells to form the enteroendocrine cells. The upregulation of ChgA is such that the fraction of cells expressing CGA in the obtained cell population, as measured by a ChgA Immunostaining Assay, is at least about 1.5%. Small molecules that can be used to differentiate the post-natal cells into the enteroendocrine cells can include at least one of a Wnt activator, a Notch inhibitor, a Wnt inhibitor, a MEK/ERK inhibitor, a growth factor, a HDAC inhibitor, a Histone Methylation Inhibitor, a Tgf-β inhibitor, and a NeuroD1 activator. Also, the insulin expression of a population of mammalian cells is increased by treating the population with a plurality of small molecules that increase the insulin expression.

An in vitro microfluidic gut-on-chip is described herein that mimics the structure and at least one function of specific areas of the gastrointestinal system in vivo. In particular, a multicellular, layered, microfluidic culture is described, allowing for interactions between lamina propria-derived cells and gastrointestinal epithelial cells and endothelial cells. This in vitro microfluidic system can be used for modeling inflammatory gastrointestinal tissue, e.g., Crohn's disease, colitis and other inflammatory gastrointestinal disorders. These multicellular, layered microfluidic gut-on-chip further allow for comparisons between types of gastrointestinal tissues, e.g., small intestinal deuodejeum, small intestinal ileium, large intestinal colon, etc., and between disease states of gastrointestinal tissue, i.e. healthy, pre-disease and diseased areas. Additionally, these microfluidic gut-on-chips allow identification of cells and cellular derived factors driving disease states and drug testing for reducing inflammation.

Various embodiments of the invention provide methods of treating diabetes and other glucose regulation disorders. In one embodiment, the method comprises removing L-cells from a donor, obtaining stem cells from a patient, and culturing the L-cells in the presence of the stem cells under conditions such that the stem cells differentiate into stem cell-derived L-cells (SCDLC). An amount of the SCDLC is introduced into the patient sufficient to cause a lowering of the patient's blood glucose level after ingestion of food. In another embodiment, the method comprises removing K-cells from a donor, obtaining stem cells from a patient, and culturing the K-cells in the presence of the stem cells under conditions such that the stem cells differentiate into stem cell-derived K-cells (SCDKC). An amount of the SCDKC is introduced into the patient sufficient to cause a lowering of the patient's blood glucose level after ingestion of food.

Disclosed are methods of assessing the ability of a candidate therapeutic agent to reverse, reduce or prevent intestinal injury by a potential toxic agent using a three-dimensional, engineered, bioprinted, biological intestinal tissue model. Also disclosed are methods of assessing the effect of an agent on intestinal function, the method comprising contacting the agent with a three-dimensional, engineered, bioprinted, biological intestinal tissue model.

An in vitro microfluidic gut-on-chip is described herein that mimics the structure and at least one function of specific areas of the gastrointestinal system in vivo. In particular, a multicellular, layered, microfluidic culture is described, allowing for interactions between lamina propria-derived cells and gastrointestinal epithelial cells and endothelial cells. This in vitro microfluidic system can be used for modeling inflammatory gastrointestinal tissue, e.g., Crohn's disease, colitis and other inflammatory gastrointestinal disorders. These multicellular, layered microfluidic gut-on-chip further allow for comparisons between types of gastrointestinal tissues, e.g., small intestinal deuodejeum, small intestinal ileium, large intestinal colon, etc., and between disease states of gastrointestinal tissue, i.e. healthy, pre-disease and diseased areas. Additionally, these microfluidic gut-on-chips allow identification of cells and cellular derived factors driving disease states and drug testing for reducing inflammation.

Devices, systems, and techniques are described for printing pre-aligned microtissues into larger tissue constructs. For example, a method of printing a tissue construct includes aligning cells in a first direction to create pre-aligned microtissues, suspending the pre-aligned microtissues in a liquid to create a bioink, and depositing the pre-aligned microtissues in a second direction to create the tissue construct.

The instant disclosure relates to compositions derived from precursor cells, and methods of using such compositions, for the manufacture of hematopoietic stem cells (HSCs) or derivative immune cells. More particularly, methods for obtaining hematopoietic stem cells from organoid tissue or cultures comprising organoids are disclosed, wherein the organoid tissue or cultures comprise liver or colonic tissue derived from precursor cells (such as embryonic stem cells or induced pluripotent stem cells), via directed differentiation.

Disclosed are methods of assessing the ability of a candidate therapeutic agent to reverse, reduce or prevent intestinal injury by a potential toxic agent using a three-dimensional, engineered, bioprinted, biological intestinal tissue model. Also disclosed are methods of assessing the effect of an agent on intestinal function, the method comprising contacting the agent with a three-dimensional, engineered, bioprinted, biological intestinal tissue model.