title: When a healthy diet turns deadly.
abstract: The health benefits of a high fiber diet (HFD) result in part from the action of metabolic end products made by gut commensals on the host epithelium. Butyrate is one such beneficial metabolite; however, butyrate paradoxically enhances the capacity of Escherichia coli-produced Shiga toxin type 2 (Stx2) to kill tissue culture cells. We recently showed that mice fed an HFD exhibited increased butyrate in gut contents and had an altered intestinal microbiota with reduced numbers of Escherichia species. Furthermore, mice fed an HFD and infected with Stx-producing E. coli (STEC) were colonized to a higher degree, lost more weight and succumbed to infection at greater rates compared with STEC-infected low fiber diet animals. The HFD animals showed higher levels of the Stx receptor globotriaocylceramide (Gb3) in both the gut and kidneys. We speculate that an HFD that leads to increased intestinal butyrate and Gb3 in the intestines and kidneys may explain the higher rate of the hemolytic uremic syndrome in females over males.
authors.affiliation: Department of Microbiology and Immunology; Uniformed Services University of the Health Sciences; Bethesda, MD USA.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Zumbrun
authors.affiliation: Department of Microbiology and Immunology; Uniformed Services University of the Health Sciences; Bethesda, MD USA.
authors.forename: Angela R
authors.initials: AR
authors.lastname: Melton-Celsa
authors.affiliation: Department of Microbiology and Immunology; Uniformed Services University of the Health Sciences; Bethesda, MD USA.
authors.forename: Alison D
authors.initials: AD
authors.lastname: O'Brien
mesh_terms: D000818:Animals; D002087:Butyrates / Q000378:metabolism*; D004043:Dietary Fiber / Q000494:pharmacology*; D004198:Disease Susceptibility / Q000382:microbiology*; D004927:Escherichia coli Infections / Q000517:prevention & control*; D019453:Escherichia coli O157 / Q000502:physiology*; D041981:Gastrointestinal Tract / Q000382:microbiology*; D006801:Humans
chemical_list: D002087:Butyrates; D004043:Dietary Fiber
keywords: Escherichia coliO157:H7; Shiga toxin; butyrate; colon; diet; globotriaosylceramide; hemolytic uremic syndrome; kidney; microbiota