Bowel preparation before colonoscopy: Consequences, mechanisms, and treatment of intestinal dysbiosis

Table 1 Research associated with the effects of bowel preparation on the gut microbiota

Year of research	Ref.	Subjects	Sample	Bowel-preparation regimen	Research methods	Conclusion
2006	Mai et al[16]	2 Polyps + 1 intestinal inflammation + 2 negative colonoscopy	Feces	Unknown	DGGE	BP and colonoscopy may have a considerable effect on gut microbiota
2012	Harrell et al[17]	12 healthy adults	Mucosa	4 L PEG	16S rRNA sequencing	BP (not diet, etc.) affects the gut mucosal microbiota
2013	O’Brien et al[18]	20 adults	Feces	10 mg bisacodyl + 2 L PEG	DGGE + 16S rRNA sequencing	BP had no lasting considerable effect on gut microbiota
2013	Gorkiewicz et al[19]	4 healthy adults	Feces + mucosa	PEG (150 g/day, 3 days)	16S rRNA sequencing	PEG caused changes in fecal and colonic mucosal microbiota similar to the gut microbiota in IBD
2015	Jalanka et al[20]	23 healthy adults	Feces	PEG 1 + 1 L/2 L1	16S rRNA sequencing	The effect of BP on gut microbiota was transient, and the effect of 1 L + 1 L PEG regimen was smaller
2016	Drago et al[21]	10 adults with a positive FOBT and negative colonoscopy	Feces	PEG 4 L	16S rRNA sequencing	BP had long-lasting effects on the gut microbiota
2016	Shobar et al[22]	8 IBD + 10 healthy adults	Feces + mucosa	Unknown	16S rRNA sequencing	Short-term changes in fecal and luminal microbiota occurred after BP
2017	Shaw et al[23]	16 children	Feces + mucosa + swab	Sodium picosulfate with magnesium citrate and senna	16S rRNA sequencing	BP in the pediatric population did not result in sustained changes in the gut microbiota
2018	Chen et al[24]	20 overweight male adults with negative colonoscopy	Feces	Sodium phosphate	16S rRNA sequencing	In the 28 days after BP, the dominant bacteria genus changed little, and the influence on the prevotella group was relatively greater
2019	Nagata et al[25]	31 adults (23 control subjects were obtained from a published paper)	Feces	Sdium picosulfate with magnesium citrate and senna	16S rRNA sequencing + CE-TOF-MS	BP had a notable effect on the gut microbiota and its metabolism, but it basically recovered within 14 days
2020	Deng et al[26]	32 adults	Feces	PEG 2 L	16S rRNA sequencing	BP considerably altered the gut microbiota, and probiotics promoted the recovery of dysbiosis
2020	Hegelmaier et al[27]	16 Adults with Parkinson	Feces	Dietary intervention alone or additional enema	16S rRNA sequencing	Dietary intervention and bowel cleansing can help alleviate PD
2021	Wang et al[28]	128 healthy adults	Feces	Split-dose PEG	16S rRNA sequencing	Colonoscopy can cause temporary changes in gut microbiota, slow recovery in the elderly, and probiotics can speed up recovery
2022	Yang et al[30]	81 elderly patients with gastric cancer	Feces	PEG (2-4 L)	16S rRNA sequencing	BP altered the gut microbiota composition of patients with gastric cancer
2022	Powles et al[29]	2 UC + 9 healthy adults	Feces + urine	MoviPrep (with PEG, electrolyte, etc.)	16S rRNA sequencing	BP temporarily reduced α diversity, but had no notable effect on fecal and urine metabolic profiles
2023	Zou et al[31]	19 children	Feces	Split-dose PEG	Metagenomic sequencing	PEG can affect the gut microbiota in children, most of which recovered within two weeks

¹Jalanka et al[20] administered a divided dose of polyethylene glycol (1 L per dose, twice) to one group of subjects, and a single dose (2 L per dose) to another group.

BP: Bowel preparation; PEG: Polyethylene glycol; UC: Ulcerative colitis; IBD: Inflammatory bowel disease.