In mouse and gut-on-a-chip models, pre-colonoscopy bowel preparation promotes pathogen colonization of the gut and translocation to other organs

In the United States, an estimated 14 million colonoscopies are performed yearly, each requiring patients to undergo bowel preparation, a laxative cleansing of the intestine's luminal contents. Despite the widespread use of bowel preparation, its effects on the gut and susceptibility to pathogens remains poorly understood, particularly for patients with compromised gut health. Using mouse and gut-on-a-chip models, we found that bowel preparation with the laxative polyethylene glycol rapidly alters the gut environment in multiple ways, making it more susceptible to colonization by both Salmonella , including a non-motile mutant normally unable to invade the gut, and gut pathobionts from an ulcerative colitis microbiota. In addition, bowel preparation promotes the translocation of these bacteria from the mouse gut to extraintestinal organs, such as nearby lymph nodes, the liver, and spleen. These findings suggest that bowel preparation may have clinical implications that are not currently appreciated.