title: Laxative treatment with polyethylene glycol decreases microbial primary bile salt dehydroxylation and lipid metabolism in the intestine of rats.
abstract: Polyethylene glycol (PEG) is a frequently used osmotic laxative that accelerates gastrointestinal transit. It has remained unclear, however, whether PEG affects intestinal functions. We aimed to determine the effect of PEG treatment on intestinal sterol metabolism. Rats were treated with PEG in drinking water (7%) for 2 wk or left untreated (controls). We studied the enterohepatic circulation of the major bile salt (BS) cholate with a plasma stable isotope dilution technique and determined BS profiles and concentrations in bile, intestinal lumen contents, and feces. We determined the fecal excretion of cholesterol plus its intestinally formed metabolites. Finally, we determined the cytolytic activity of fecal water (a surrogate marker of colorectal cancer risk) and the amount and composition of fecal microbiota. Compared with control rats, PEG treatment increased the pool size (+51%; P < 0.01) and decreased the fractional turnover of cholate (-32%; P < 0.01). PEG did not affect the cholate synthesis rate, corresponding with an unaffected fecal primary BS excretion. PEG reduced fecal excretion of secondary BS and of cholesterol metabolites (each P < 0.01). PEG decreased the cytolytic activity of fecal water [54 (46-62) vs. 87 (85-92)% erythrocyte potassium release in PEG-treated and control rats, respectively; P < 0.01]. PEG treatment increased the contribution of Verrucomicrobia (P < 0.01) and decreased that of Firmicutes (P < 0.01) in fecal flora. We concluded that PEG treatment changes the intestinal bacterial composition, decreases the bacterial dehydroxylation of primary BS and the metabolism of cholesterol, and increases the pool size of the primary BS cholate in rats.
authors.affiliation: Univ. Medical Center Groningen, Beatrix Children's Hospital, Div. Pediatric Gastroenterology and Hepatology, P.O. Box 30.001, 9700 RB Groningen, The Netherlands. m.y.m.van.der.wulp@umcg.nl.
authors.forename: Mariëtte Y M
authors.initials: MY
authors.lastname: van der Wulp
authors.forename: Muriel
authors.initials: M
authors.lastname: Derrien
authors.forename: Frans
authors.initials: F
authors.lastname: Stellaard
authors.forename: Henk
authors.initials: H
authors.lastname: Wolters
authors.forename: Michiel
authors.initials: M
authors.lastname: Kleerebezem
authors.forename: Jan
authors.initials: J
authors.lastname: Dekker
authors.forename: Edmond H H M
authors.initials: EH
authors.lastname: Rings
authors.forename: Albert K
authors.initials: AK
authors.lastname: Groen
authors.forename: Henkjan J
authors.initials: HJ
authors.lastname: Verkade
mesh_terms: D000818:Animals; D001647:Bile Acids and Salts / Q000378:metabolism*; D005243:Feces; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000187:drug effects* / Q000382:microbiology; D054368:Laxatives / Q000494:pharmacology; D050356:Lipid Metabolism / Q000187:drug effects*; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar
chemical_list: D001647:Bile Acids and Salts; D054368:Laxatives; D011092:Polyethylene Glycols
keywords: bile salt; cholate; enterohepatic circulation; microbiota