Fish oil is more potent than flaxseed oil in modulating gut microbiota and reducing trimethylamine-N-oxide (TMAO)-exacerbated atherogenesis

Trimethylamine-N-oxide (TMAO) is a risk factor for atherosclerosis. We compared the potency of fish oil with flaxseed oil in reducing TMAO-exacerbated atherogenesis. Five groups of ApoE-/- mice were given one of five diets, namely a low-fat diet, a Western high fat diet (WD), a WD plus 0.2% TMAO, and two WD diets containing 0.2% TMAO with 50% lard being replaced by flaxseed oil or fish oil. TMAO accelerated atherosclerosis and disturbed cholesterol homeostasis. Compared with flaxseed oil, fish oil was more effective in inhibiting TMAO-induced atherogenesis by lowering plasma cholesterol and inflammatory cytokines. Both oils could reverse TMAO-induced decrease in fecal acidic sterols. Fish oil promoted fecal output of neutral sterols and down-regulated hepatic cholesterol biosynthesis. Fish oil was more effective than flaxseed oil in promoting the growth of short chain fatty acids-producing bacteria and lowering microbial generation of lipopolysaccharide. In conclusion, fish oil is more potent than flaxsee...