The influence of combined buckwheat D-fagomine and fish omega-3 PUFAs on beneficial gut bacteria in rats

Abstract

Some functional food components may help maintain homeostasis by promoting balanced gut microbiota. Here, we explore the possible complementary effects of D-fagomine and ω-3 PUFAs (EPA/DHA 1:1) on putatively beneficial gut bacterial strains associated with inflammatory processes and cardiovascular health. Male Sprague Dawley rats were supplemented with d-fagomine, ω-3 PUFAs, or both, for 21 weeks. Body weight, energy intake and plasma lipid profile were monitored. Bacterial subgroups were evaluated in fecal DNA by qRT-PCR and short-chain fatty acids were determined by gas chromatography. Pro-inflammatory arachidonic acid (ARA)-derived metabolites were determined by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). We found that the populations of the genus Prevotella (putatively beneficial bacteria associated with dietary fiber) remained stable over time in animals supplemented with D-fagomine, independently of ω-3 PUFA supplementation. D-Fagomine supplementation also maintained the relative populations of Bifidobacteriales, while ω-3 PUFAs mainly affected Lactobacilliales. ω-3 PUFAs reduced the amount of the short-chain fatty acid (SCFA) acetic acid in feces. Reduced levels of SCFAs ratios may indicate increased intestinal absorption and they have consistently been associated with the lean healthy phenotype, compared to metabolically altered phenotypes. Animals supplemented with D-fagomine gained less weight and tended to accumulate less fat than controls and rats given only ω-3 PUFAs. The plasma levels of pro-inflammatory ARA-derived metabolites, triglycerides and cholesterol were lower in groups supplemented with ω-3 PUFAs. The anti-inflammatory action of ω-3 PUFAs may in part be mediated by an increase in acetate absorption in the intestinal tract. The effects of D-fagomine and ω-3 PUFA on healthy rats given a standard diet appear to be complementary. D-Fagomine predominantly affected weight gain and stabilizes the populations of putatively beneficial bacteria while EPA/DHA 1:1 reduced pro-inflammatory metabolites. The combination between D-fagomine and ω-3 PUFAs provided the functional benefits of each supplement. Notably, it helped stabilize populations of Prevotella in the rat intestinal tract while reducing weight gain and providing the anti-inflammatory and cardiovascular benefits of ω-3 PUFAs