title: Dietary oils modify the host immune response and colonic tissue damage following Citrobacter rodentium infection in mice.
abstract: Inflammatory bowel disease is an intestinal inflammatory disorder of multifactorial origin, in which diets that favor high n-6 and low n-3 fatty acids have been implicated. The present study addressed whether dietary n-6 and n-3 fatty acids alter colonic mucosal response to Citrobacter rodentium (C. rodentium) infection. Mice were fed diets identical except for fatty acids, with an energy percentage of 15% 18:2n-6 and <0.06% 18:3n-3, 4.2% 18:2n-6 and 1.9% 18:3n-3, or 1.44% 20:5n-3, 4.9% 22:6n-3, 0.32% 18:2n-6, and 0.12% 18:3n-3 from safflower, canola, or fish oil, respectively for 3 wk before infection. Dietary oils had no effect on colonic C. rodentium growth but altered colon 20:4n-6/(20:5n-3+22:6n-3) with 9.40 ± 0.06, 1.94 ± 0.08, and 0.32 ± 0.03% in colon phosphatidylcholine and 3.82 ± 0.18, 1.14 ± 0.02, and 0.30 ± 0.02% in phosphatidylethanolamine of mice fed safflower, canola, or fish oil, respectively. At 10 days postinfection, histological damage, F4/80-positive macrophages, and myeloperoxidase-positive neutrophils in colonic mucosa were higher in infected mice fed safflower than fish oil. Colon gene transcripts for macrophage inflammatory protein 2, keratinocyte cytokine, and monocyte chemoattractant protein 1 expression were significantly higher in infected mice fed safflower than canola or fish oil; IFN-γ, IL-6, and IL-17A expression were significantly elevated in mice fed safflower rather than fish oil; and IL-10 was significantly higher in mice fed fish oil rather than canola or safflower oil. This study demonstrates that oils high in 18:2n-6 with minimal n-3 fatty acids exacerbate mucosal immune response, whereas oils high in n-3 fatty acids attenuate mucosal immune response to C. rodentium. These studies implicate dietary oils as environmental modifiers of intestinal inflammation in response to infection.
authors.affiliation: Div. of Gastroenterology, B.C. Children's Hospital, 4480 Oak St., Rm. K4-181, Vancouver, BC, Canada V6H 3V4.
authors.forename: Azita
authors.initials: A
authors.lastname: Hekmatdoost
authors.forename: Xiujuan
authors.initials: X
authors.lastname: Wu
authors.forename: Vijay
authors.initials: V
authors.lastname: Morampudi
authors.forename: Sheila M
authors.initials: SM
authors.lastname: Innis
authors.forename: Kevan
authors.initials: K
authors.lastname: Jacobson
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D058491:Bacterial Load; D049109:Cell Proliferation / Q000187:drug effects; D044082:Citrobacter rodentium; D003092:Colitis / Q000473:pathology; D003106:Colon / Q000378:metabolism / Q000473:pathology*; D016207:Cytokines / Q000032:analysis / Q000378:metabolism; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology*; D004756:Enterobacteriaceae Infections / Q000276:immunology* / Q000473:pathology*; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology; D043371:Fatty Acids, Omega-6 / Q000494:pharmacology; D005243:Feces / Q000382:microbiology; D016650:Fluorescein-5-isothiocyanate; D005455:Fluorescent Antibody Technique; D007109:Immunity / Q000187:drug effects*; D007249:Inflammation / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D010539:Permeability; D010743:Phospholipids / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D016207:Cytokines; D004042:Dietary Fats, Unsaturated; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D010743:Phospholipids; D016650:Fluorescein-5-isothiocyanate
keywords: Citrobacter rodentium colitis; dietary oils; fish oil; safflower oil