Effects of trans-10, cis-12-conjugated linoleic acid on mice are influenced by the dietary fat content and the degree of murine obesity

Trans-10, cis-12-conjugated linoleic acid (t10c12-CLA) has been reported to induce body fat loss with the side effects of liver steatosis and the development of diabetes. To investigate whether the dietary fat content may influence the response to t10c12-CLA in animals, t10c12-producing recombinant food-grade Lactococcus lactis transformed with the pai isomerase gene was used to feed lean, obesity-induced, or obese mice. Compared with the non-CLA producing recombinant, the significant (p<0.05) changes in the lean mice were the loss of body weight and abdominal adipose tissue (p<0.05), reduced ratios of total cholesterol/HDL, and LDL/HDL (p<0.05), and an early hepatic steatosis. In obesity-induced mice, the body weight and abdominal adipose tissue were unexpectedly increased (p<0.05) with an elevated TG/HDL ratio (p<0.05). In obese mice, only the ratios of LDL/HDL and total cholesterol/HDL were significantly (p<0.05) reduced. In addition, within three groups, certain changes in fatty acid composition also occurred in various organs and tissues. These results suggest that the dietary fat level and host obesity can alter the response to t10c12-CLA in animals.