Melgaço ACC, Alves AF, Pessoa WFB. Polyethylene glycol-based bowel preparation and gut dysbiosis: Clinical implications beyond colon cleansing. World J Gastroenterol 2026; 32(35): 118836 [DOI: 10.3748/wjg.118836]
Corresponding Author of This Article
Wallace Felipe Blohem Pessoa, PhD, Adjunct Professor, Department of Biomedical Sciences, Federal University of Paraíba, Via Pau Brasil, S/N, João Pessoa 58050-585, Paraíba, Brazil. wall.bmd@gmail.com
Research Domain of This Article
Microbiology
Article-Type of This Article
review-article
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This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
World J Gastroenterol. Sep 21, 2026; 32(35): 118836 Published online Sep 21, 2026. doi: 10.3748/wjg.118836
Polyethylene glycol-based bowel preparation and gut dysbiosis: Clinical implications beyond colon cleansing
Ana Clara Correia Melgaço, Adriano Francisco Alves, Wallace Felipe Blohem Pessoa
Ana Clara Correia Melgaço, Department of Biological Sciences, State University of Santa Cruz, Ilhéus 45662-900, Bahia, Brazil
Adriano Francisco Alves, Wallace Felipe Blohem Pessoa, Department of Biomedical Sciences, Federal University of Paraíba, João Pessoa 58050-585, Paraíba, Brazil
Author contributions: Pessoa WFB contributed to conceptualization, writing, reviewing and editing; Melgaço ACC and Alves AF wrote the original draft; Melgaço ACC and Alves AF participated in drafting the manuscript; and all authors have read and approved the final version of the manuscript.
AI contribution statement: The scientific concepts, manuscript structure, literature selection, interpretation of evidence, critical analysis, and final intellectual content were conceived, developed, and validated by the authors. ChatGPT was used to assist with language refinement, grammar correction, sentence restructuring, improvement of readability, and editorial polishing of selected sections of the manuscript. All AI-assisted suggestions were critically reviewed, modified when necessary, and approved by the authors. The AI tool did not participate in study conception, literature selection, scientific interpretation, critical analysis, formulation of hypotheses, or development of conclusions.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
Corresponding author: Wallace Felipe Blohem Pessoa, PhD, Adjunct Professor, Department of Biomedical Sciences, Federal University of Paraíba, Via Pau Brasil, S/N, João Pessoa 58050-585, Paraíba, Brazil. wall.bmd@gmail.com
Received: January 20, 2026 Revised: February 16, 2026 Accepted: June 9, 2026 Published online: September 21, 2026 Processing time: 211 Days and 12.3 Hours
Abstract
Owing to their efficacy and safety profile, polyethylene glycol (PEG)-based formulations are the gold standard for bowel preparation before colonoscopy and colorectal surgery. However, PEG lavage may transiently disrupt gut microbial diversity, reduce short-chain fatty acid-producing bacteria, alter mucus barrier integrity, and promote the expansion of opportunistic taxa. These ecological alterations may influence mucosal recovery, immune homeostasis, and susceptibility to inflammatory or infectious complications, particularly in vulnerable individuals. Nevertheless, current evidence remains heterogeneous, and direct causal relationships between PEG-induced dysbiosis and adverse clinical outcomes remain indefinite. Accordingly, this opinion review critically discusses the mechanisms underlying PEG-associated microbiota disruption, including mechanical washout, osmotic stress, mucus layer alterations, and metabolic depletion. The review also examines the potential implications for infection risk, immune modulation, and postoperative outcomes while highlighting the limitations and controversies surrounding the interpretation of microbiome studies. Finally, the review discusses emerging strategies aimed at minimizing ecological disruption while preserving bowel cleansing efficacy.
Core Tip: Polyethylene glycol (PEG)-based bowel preparation may transiently alter gut microbial diversity, mucus barrier integrity, and short-chain fatty acid production. Although these ecological changes are increasingly associated with immune modulation and postoperative outcomes, current evidence remains heterogeneous and largely observational. Suitably, this opinion review critically examines the mechanisms and potential clinical implications of PEG-induced dysbiosis. The review also emphasizes the need for microbiota-preserving bowel preparation strategies and personalized approaches based on host resilience and baseline microbiota composition.
