Probing Clostridium difficile Infection in Complex Human Gut Cellular Models

Interactions of anaerobic gut bacteria, such as , with the intestinal mucosa have been poorly studied due to challenges in culturing anaerobes with the oxygen-requiring gut epithelium. Although gut colonization by is a key determinant of disease outcome, precise mechanisms of mucosal attachment and spread remain unclear. Here, using human gut epithelial monolayers co-cultured within dual environment chambers, we demonstrate that adhesion to gut epithelial cells is accompanied by a gradual increase in bacterial numbers. Prolonged infection causes redistribution of actin and loss of epithelial integrity, accompanied by production of spores, toxins, and bacterial filaments. This system was used to examine interactions with the commensal , and interestingly, growth is significantly reduced in the presence of . Subsequently, we have developed novel models containing a myofibroblast layer, in addition to the epithelium, grown on polycarbonate or three-dimensional (3D) electrospun scaffolds. In these more complex models, adheres more efficiently to epithelial cells, as compared to the single epithelial monolayers, leading to a quicker destruction of the epithelium. Our study describes new controlled environment human gut models that enable host-anaerobe and pathogen-commensal interaction studies .