Ground flaxseed reverses protection of a reduced-fat diet against Citrobacter rodentium-induced colitis

Abstract

Flaxseed is high in omega-3 polyunsaturated fatty acids, fiber and lignans known to lower cholesterol levels. However, its use for prevention or treatment of inflammatory bowel diseases has yielded mixed results, perhaps related to dietary interactions. In this study, we evaluated the impact of ground flaxseed supplementation on the severity of Citrobacter rodentium-induced colitis in the setting of either a high fat (HF; ~36 %kcal) or reduced fat (RF; ~12 %kcal) diet. After weaning, C57BL/6 mice (n=8-15/treatment) were fed ground flaxseed (7g/100g diet) with either HF (HF Flx) or RF (RF Flx) diets for four weeks prior to infection with C. rodentium or sham gavage. Weight changes, mucosal inflammation, pathogen burden, gut microbiota composition, tissue polyunsaturated fatty acids and cecal short-chain fatty acids were compared over a 14-day infection period. A RF diet protected against C. rodentium-induced colitis, whereas a RF Flx diet increased pathogen burden, exacerbated gut inflammation and promoted gut dysbiosis. Compared with a RF diet, both HF and HF Flx diets resulted in more severe pathology in response to C. rodentium infection. Our findings demonstrate that although a RF diet protected against C. rodentium-induced colitis and associated gut dysbiosis in mice, beneficial effects were diminished with ground flaxseed supplementation.

The Canonical Long-Chain Fatty Acid Sensing Machinery Processes Arachidonic Acid To Inhibit Virulence in Enterohemorrhagic Escherichia coli

“…Manipulation of lipid content in host tissues, including omega-6 PUFAs such as arachidonic acid (C 20:4 ) and omega-3 PUFAs such as alpha-linoleic acid (C 18:3 ), eicosapentaenoic acid (C 20:5 ), and docosahexaenoic acid (C 22:6 ), through dietary, genetic, or pharmacological interventions is associated with altered severity of disease in numerous experimental models of colitis (55,56). In the context of enteric bacterial infection, the administration of different dietary oil supplements can alter disease outcomes in mice challenged with Citrobacter rodentium, a murine pathogen that serves as an established model for human EHEC and enteropathogenic E. coli (EPEC) infection (57)(58)(59)(60)(61). Given the high fat content and increased omega-6-to-omega-3 ratios characteristic of the Western diet, there is much interest in defining the molecular mechanisms by which specific PUFAs may modulate the outcomes of intestinal diseases such as enteric infection.…”

Plant‐ and Fish‐Derived n‐3 PUFAs Suppress Citrobacter Rodentium–Induced Colonic Inflammation

“…AO dose‐dependently increases plasma and mononuclear levels of ALA, ETA, and DPA, and enhances interleukin‐10 expression in response to LPS . We previously reported that whole flaxseed reverses the protective effects of a reduced fat diet on C. rodentium colitis at a dose similar to the n ‐3 PUFA oil content tested here . Importantly, the present study suggests that the observed negative effects were not due to flaxseed meal oil content per se, but rather due to other components present in the seed.…”

Dietary Flaxseed as a Strategy for Improving Human Health

“…For example, a 5% flaxseed supplemented diet had no protective effect against the development of intestinal tumours [83]. Caution in the use of flaxseed in the diet has also been introduced by the results of Maatanen and co-workers, who showed that whereas a reduced fat diet could protect against colitis, the high levels of PUFAs provided by flaxseed supplementation to the diet diminished these beneficial effects [84].…”