Effects of lactic acid bacteria on low-density lipoprotein susceptibility to oxidation and aortic fatty lesion formation in hyperlipidemic hamsters.

We investigated the effects of Streptococcus thermophilus YIT 2001, a strain of lactic acid bacteria, on the susceptibility of low-density lipoprotein (LDL) to oxidation and the formation of aortic fatty lesions in hyperlipidemic hamsters. S. thermophilus YIT 2001 had the highest in vitro antioxidative activity against LDL oxidation among the 79 strains of lactic acid bacteria and bifidobacteria tested, which was about twice that of S. thermophilus YIT 2084. The lag time of LDL oxidation in the YIT 2001 feeding group was significantly longer than in controls, but was unchanged in the YIT 2084 group. After the feeding of YIT 2001, lag times were prolonged and areas of aortic fatty lesions were dose-dependently attenuated, although there were no effects on plasma lipid levels. These results suggest that YIT 2001 has the potential to prevent the formation of aortic fatty lesions by inhibiting LDL oxidation.