The results of this study demonstrate that, as compared toconsumption of traditional yogurt with 1.0% milk fat, theingestion, three times a day, of 125 ml milk, fermented bytraditional yogurt starters and two selected strains ofLactobacillus acidophilus, and containing 2.5% fructooligosaccharides, 0.5% vegetable oil and 0.5% milk fat,signi®cantly (P < 0.005) lowered the serum LDL-cholesterol by on average 5.4% after three weeks in healthy maleadults with borderline elevated levels of seum total cholesterol. Almost all of the effect was attributable to eitherLactobacillus acidophilus, the fructo-oligosaccharides, orto a combination of these factors. The potential dose andtime dependency of the effects on serum cholesterol valuesneeds to be assessed