Clostridioides difficile Stimulates CCL20 Expression in Human Colonoid Monolayers in a Transwell-Based Coculture System That Supports Its Anaerobic Growth.

The pathogenic bacterium Clostridioides difficile is a major cause of antibiotic-associated diarrheal disease. Treatment of the disease is challenging because antibiotics used for treatment may also perpetuate the conditions that contributed to initial susceptibility. Elucidating the mechanisms of C. difficile/intestinal epithelium interaction is needed to facilitate the development of new therapeutic options. The studies described in this communication demonstrate the development of a tissue culture system that supported the growth of C. difficile in coculture with a model of the human intestinal epithelium produced from colonoids, organoids derived from human colonic biopsies. Epithelial cell responses to C. difficile included upregulation of CCL20, encoding a chemokine that was previously shown to be upregulated in response to C. difficile challenge. Additionally, bacteria associated with the monolayer in a nontoxin-dependent manner. This system will support future investigation of epithelium/C. difficile interactions during CDI and identification of mechanisms that drive pathogenesis by C. difficile in the human intestine.