Dietary Modulation of Host-Microbe Interactions

Bibliographic Details
Main Author: Nickerson, Kourtney P.
Language:English
Published: Case Western Reserve University School of Graduate Studies / OhioLINK 2014
Subjects:
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=case1386343814
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-case13863438142021-08-03T06:20:51Z Dietary Modulation of Host-Microbe Interactions Nickerson, Kourtney P. Microbiology Inflammatory bowel disease (IBD) is a chronic, debilitating intestinal disease affecting an estimated 1.3 million individuals in the United States alone, with worldwide incidence rapidly rising. Crohn’s Disease (CD), one subtype of IBD, is believed to arise in response to environmental priming resulting in inappropriate immune responses against commensal bacteria in a genetically susceptible individual. While the scientific community has made great progress in understanding the genetics and altered immune responses observed in CD patients, little is known about the environmental factors important in shaping disease.Sugar consumption and artificial sweeteners, as well as a “Western” diet, are environmental factors associated with onset of CD. We broadly hypothesized that diet was driving changes in bacterial adhesion promoting disease onset. We identified a polymer of glucose, maltodextrin (MDX), that modulates both bacterial interaction with the environment as well as cellular response to intracellular bacteria. MDX was identified as a phenotype-enhancing compound after panels of Escherichia coli species were subjected to an array of polysaccharides. Strains of adherent-invasive E. coli have been isolated from inflamed lesions of CD patients, while changes in spatial organization of the CD microbiome results in a bacterial biofilm adherent to the- 11 -intestine epithelium. E. coli species exhibit significant increases in bacterial adhesion after exposure to MDX and isolation of bacterial DNA from ileal CD patients had higher levels of the gene MalX, a bacterial gene require for metabolism of MDX. These data suggests the polysaccharide MDX can promote E. coli adhesion and may influence bacterial populations in CD patients.Genetic studies have identified clusters of CD-associated genes in antibacterial pathways; therefore we looked at the effect of cellular MDX in the context of intracellular bacterial clearance. Exposure of cells to MDX impaired intracellular Salmonella clearance through alterations in trafficking resulting in enhanced Salmonella viability. Similar results were observed in mice infected with Salmonella, 100-fold more viable bacteria recovered from the cecum of MDX fed mice. Our work identifies a role for the polysaccharide MDX in shaping host-microbial interactions which may be important for development of chronic disease states like CD. 2014-02-21 English text Case Western Reserve University School of Graduate Studies / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=case1386343814 http://rave.ohiolink.edu/etdc/view?acc_num=case1386343814 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Microbiology
spellingShingle Microbiology
Nickerson, Kourtney P.
Dietary Modulation of Host-Microbe Interactions
author Nickerson, Kourtney P.
author_facet Nickerson, Kourtney P.
author_sort Nickerson, Kourtney P.
title Dietary Modulation of Host-Microbe Interactions
title_short Dietary Modulation of Host-Microbe Interactions
title_full Dietary Modulation of Host-Microbe Interactions
title_fullStr Dietary Modulation of Host-Microbe Interactions
title_full_unstemmed Dietary Modulation of Host-Microbe Interactions
title_sort dietary modulation of host-microbe interactions
publisher Case Western Reserve University School of Graduate Studies / OhioLINK
publishDate 2014
url http://rave.ohiolink.edu/etdc/view?acc_num=case1386343814
work_keys_str_mv AT nickersonkourtneyp dietarymodulationofhostmicrobeinteractions
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