Pasture v. standard dairy cream in high-fat diet-fed mice: improved metabolic outcomes and stronger intestinal barrier

Abstract

Dairy products derived from the milk of cows fed in pastures are characterised by higher amounts of conjugated linoleic acid and α-linolenic acid (ALA), and several studies have shown their ability to reduce cardiovascular risk. However, their specific metabolic effects compared with standard dairy in a high-fat diet (HFD) context remain largely unknown; this is what we determined in the present study with a focus on the metabolic and intestinal parameters. The experimental animals were fed for 12 weeks a HFD containing 20 % fat in the form of a pasture dairy cream (PDC) or a standard dairy cream (SDC). Samples of plasma, liver, white adipose tissue, duodenum, jejunum and colon were analysed. The PDC mice, despite a higher food intake, exhibited lower fat mass, plasma and hepatic TAG concentrations, and inflammation in the adipose tissue than the SDC mice. Furthermore, they exhibited a higher expression of hepatic PPARα mRNA and adipose tissue uncoupling protein 2 mRNA, suggesting an enhanced oxidative activity of the tissues. These results might be explained, in part, by the higher amounts of ALA in the PDC diet and in the liver and adipose tissue of the PDC mice. Moreover, the PDC diet was found to increase the proportions of two strategic cell populations involved in the protective function of the intestinal epithelium, namely Paneth and goblet cells in the small intestine and colon, compared with the SDC diet. In conclusion, a PDC HFD leads to improved metabolic outcomes and to a stronger gut barrier compared with a SDC HFD. This may be due, at least in part, to the protective mechanisms induced by specific lipids.