The hypocholesterolemic effects of Lactobacillus acidophilus 43121 (43121) and a mixture of Lactobacillus casei and Bifidobacterium longum (MIX) were studied in hypercholesterolemia-induced pigs. Serum total cholesterol was decreased by supplementation of either 43121 or MIX, although, high-density lipoprotein cholesterol was not changed. The hypocholesterolemic effect of 43121 and MIX was mainly due to bile acid dehydroxylation, this effect being supplementation-time dependent.