Abstract
Polarized columnar epithelial cells form a delicate yet highly effective, single-cell-thick barrier that lines the intestine and other mucosal surfaces. Their function is to separate and actively affect vastly different physiological compartments—forming a challenging cellular interface between the host and the outside world. In the intestine, many potential dangers to cell function and survival transit the luminal gut environment—amplified by a hugely dense microbial community colonizing the mucosal surface.