Conjugated linoleic acid (CLA) is a group of positional and geometric isomers of conjugated dienoic derivatives of linoleic acid. CLA has been reported to be able to reduce body fat. In this study, we investigated the antidiabetic effect of fermented milk (FM) containing CLA on type II diabetes db/db mice. Mice were treated with 0.2% low FM, 0.6% high FM, or Glimepiride (GLM) for 6 wk. Our results revealed that the body weight and the levels of fasting blood glucose, serum insulin, and leptin were significantly decreased in FM fed mice compared to db/db mice. Oral glucose tolerance and insulin tolerance were significantly ameliorated in FM fed mice compared to db/db mice. Consistent with these results, the concentrations of serum total cholesterol, triglycerides, and LDL cholesterol were also significantly decreased in FM fed mice compared to db/db mice. However, the concentration of HDL cholesterol was significantly higher in FM fed mice compared to db/db mice. These results were similar to those of GLM, a commercial anti-diabetic drug. Therefore, our results suggest that FM has anti-diabetic effect as a functional food to treat type II diabetes mellitus.

has since been detected in many dairy foods and the flesh of ruminants. CLA has been actively researched (6-8) since the late 1990s. During that period, human clinical trials were conducted addressing the effects of CLA on body fat reduction, leading to an explosive growth of CLA as the first diet food product in the USA (9). CLA has been associated with a multitude of effects including anti-cancer (10), anti-diabetic (11), cholesterol-lowering (12), immune enhancement (13), and antioxidant (14) effects, and effects on women's health (15). CLA-containing foods include milk products such as milk and cheese, which are synthesized from linoleic acid by microorganisms living in the rumen of mammals (5,16,17). In addition, CLA is present in beef, chicken, eggs, and safflower seed oil (18-20). CLA is necessary to develop high value-added and high function dairy products that meet modern dairy industry standards and to develop valuable dairy products that can be imported and exported. CLA production methods involve either microbial fermentation or chemical synthesis. Linoleic Efficient conversion of conjugated linoleic acid c9,t11 by Lactobacillus fermentation from vegetable oil to generate fermented milk with high CLA content