In mouse and in vitro models, bowel preparation promotes pathogen colonization, translocation and exacerbation of inflammation

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 its widespread use, the effects of bowel preparation on gut physiology and susceptibility to pathogens remains poorly understood, particularly in individuals with compromised gut health. Using mouse and in vitro models, we found that bowel preparation with the laxative polyethylene glycol (PEG) rapidly disrupts, transiently increasing susceptibility to infection by Salmonella Typhimurium, including a non-motile mutant, and by gut pathobionts derived from ulcerative colitis microbiota. Bowel preparation also facilitated bacterial translocation to extraintestinal sites (mesenteric lymph nodes, liver, and spleen) and exacerbated inflammation in a chemically-induced colitis model. Although these findings are preclinical, they suggest that bowel preparation may have underappreciated risks in vulnerable populations, and warrant further clinical investigation.

据估算，美国每年约开展1400万例结肠镜检查，每例检查均需患者完成肠道准备——即采用泻剂清除肠腔内容物的操作。尽管肠道准备的应用极为广泛，但其对肠道生理状态与病原体易感性的影响仍未得到充分阐释，尤其是在肠道健康受损的人群中。本研究通过小鼠模型与体外模型开展实验，发现使用泻剂聚乙二醇(Polyethylene Glycol, PEG)进行肠道准备，可快速扰乱肠道稳态，短暂提升机体对鼠伤寒沙门氏菌(Salmonella Typhimurium，包括其无动力突变株)以及源自溃疡性结肠炎菌群的肠道致病共生菌的感染易感性。此外，肠道准备还可促进细菌易位至肠外组织（肠系膜淋巴结、肝脏与脾脏），并在化学诱导性结肠炎模型中加重炎症反应。尽管本研究结果尚属临床前数据，但研究提示肠道准备在脆弱人群中可能存在未被充分认知的风险，因此亟需开展进一步的临床研究。