Plant- and Fish-Derived n-3 PUFAs Suppress Citrobacter Rodentium-Induced Colonic Inflammation.

Abstract

SCOPE: Marine-derived n-3 PUFAs may ameliorate inflammation associated with inflammatory bowel diseases. Plant-derived n-3 PUFAs are thought to be inferior owing to shorter chain lengths. The aim of this study was to compare the impact of plant- and fish-derived PUFAs on murine colitis. METHODS AND RESULTS: C57BL/6 mice were fed high fat (36% kcal) diets with either 2.5% w/w sunflower oil (SO), flaxseed oil (FSO), Ahiflower^® oil (AO) or fish oil (FO). After 4 weeks, mice were orogastrically challenged with Citrobacter rodentium (10⁸ CFU) or sham gavaged. Fecal shedding was assayed at 2, 7, 10, and 14 days post infection (PI), and fecal microbiota at 14 days PI. Colonic inflammation and lipid mediators were measured. Supplementation regulated intestinal inflammation with crypt lengths being 66, 73, and 62 +/-17 μm shorter (compared to SO) for FSO, AO and FO respectively, p<0.01. FSO blunted pathogen shedding at the peak of infection and FSO and AO both enhanced fecal microbial diversity. FO attenuated levels of lipoxin and leukotriene B₄ while plant oils increased pro-resolving mediator concentrations including D, E and T-series resolvins. CONCLUSION: Plant and fish n-3 PUFAs attenuated colitis-induced inflammation while exhibiting characteristic pro-resolving lipid mediator metabolomes. Plant oils additionally promoted microbial diversity.