Impacts of different fatty acids on the gut microbiota in the murine model of postmenopause
Dietary fatty acid profile high in omega-6 polyunsaturated fatty acids (PUFAs), specifically linoleic acid (LA), and low in coconut oil saturated fatty acids (SFAs) and omega-3 PUFAs may worsen symptoms of estrogen deficiency. To investigate this hypothesis, vehicle (Veh)- or E2-treated C57BL/6J and transgenic fat-1 mice were fed high-fat diet (HFD, 45 % kcal fat) with a high LA:SFA ratio (22.5%: 8%) referred to as 22.5% LA diet or a HFD with a low LA:SFA ratio (1%: 31%) referred to as 1% LA diet for a period of 14-15 weeks. E2 treatment rescued obesity, glucose intolerance and bone loss in OVX mice. fat-1 mice fed 1% LA diet mitigated weight gain and fat accumulation in Veh-treated OVX mice. fat-1 mice fed 22.5% LA diet had increased EE and activity as wheel running in E2-treated OVX mice. Except E2 treatment, coconut oil SFAs and omega-3 FAs can protect against glucose intolerance. Apparent improvement of insulin sensitivity was achieved by E2 treatment in both WT and fat-1 mice fed 1% LA diet, while fat-1 mice fed 22.5% LA diet was protected against insulin resistance without E2 treatment. Increase of relative abundance of gut microbial taxa as SCFA producers were associated with omega-3 FAs production and improved energy homeostasis. These data suggest that a balanced dietary FA profile containing coconut oil SFAs and a lower ratio of omega-6/omega-3 FAs is a safer strategy for alleviating metabolic disorders in the status of E2 deficiency.