Lactobacillus acidophilus Attenuates Polyethylene Glycol-Induced Susceptibility to Citrobacter rodentium Infection via Microbiota Modulation

ObjectivePolyethylene glycol (PEG), a globally prevalent laxative, is extensively utilized for bowel preparation prior to colonoscopy or abdominal surgery owing to its exceptional safety profile. Nevertheless, emerging evidence suggests that PEG administration may induce significant alterations in colonic microbiota composition, with dysbiotic effects persisting for over two weeks. The potential implications of such microbiota perturbations on the colonization and invasion of opportunistic pathogens remain underexplored. Methods and AnalysisTo investigate this, we employed a murine model infected with Citrobacter rodentium (C.R.), a surrogate for Enteropathogenic Escherichia coli (EPEC) and Enterohemorrhagic Escherichia coli (EHEC), following PEG-induced bowel preparation. ResultsThe severity of infectious enteritis was assessed, and the prophylactic efficacy of Lactobacillus acidophilus (LAC) supplementation was evaluated. Our findings indicate that PEG administration significantly elevated C.R. load, enhanced virulence gene expression, and exacerbated intestinal inflammation post-infection, with the infection window extending approximately 14 days. Through fecal metagenomic analysis and co-housing experiments, we demonstrated that PEG-associated enteritis is critically mediated by gut microbiota dysbiosis. Furthermore, supplementation with LAC was shown to mitigate susceptibility to C.R. infection. ConclusionsThese results suggest that PEG increases intestinal susceptibility to infection in a microbiota-dependent manner, highlighting the therapeutic potential of LAC in restoring microbial homeostasis.