Polyethylene glycol enhances colonic barrier function and ameliorates experimental colitis in rats

Objective Polyethylene glycol (PEG) has been suggested to protect against pathogen colonization by improving colonic barrier function. We aimed to establish whether PEG 4000 affects colonic barrier function and the development of colitis induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS) in rats. Materials and methods PEG was included in the drinking water for a period of 48 h before intracolonic administration of TNBS. Results and discussion PEG increased colonic surface hydrophobicity and diminished luminal bacterial load. Moreover, PEG markedly reduced mucosal damage and inflammation induced by TNBS. This protection effect appeared to be independent of its laxative properties since the laxatives mannitol or senna extracts had no effect on TNBS colitis. Using everted colonic sacs, pretreatment with PEG produced a lasting reduction in epithelial permeability to mannitol and dextran-70 K that correlated with decreased surface hydrophobicity. Conclusion Our results suggest that the protective effect of PEG on TNBS colitis is associated with reinforcement of the epithelial barrier.