Coronary heart disease (CHD) is one of the major causes of death and disability in industrialised countries. Results from several epidemiological and clinical studies indicate a positive correlation between elevated total serum cholesterol levels, mainly reflecting the LDL-cholesterol fraction, and risk of CHD. It is thought that a reduction in total plasma cholesterol levels in populations suffering from primary hypercholesterolemia (elevated cholesterol) can lower the incidence of coronary thrombosis. Currently, therefore there is extensive interest in the management of serum cholesterol and other blood lipids. Diet is viewed as a major influencing factor that can reduce levels. This is largely driven by the expense of drug therapy, the large numbers of individuals affected and unwanted side effects of such treatments. Dietary strategies for prevention of CHD implicate adherence to a low-fat/low-saturated fat diet. Although such diets may present an effective approach, they are difficult to maintain on a long-term basis and efficacy diminishes over time. As such, new approaches towards identification of other dietary means of reducing blood cholesterol levels have been evaluated. These include, among others, the use of probiotics. Probiotics are 'live microbial feed supplements that offer a benefit to health'. They are marketed as health or functional foods whereby they are ingested for their purported positive advantages in the digestive tract and/or systemic areas like the liver, vagina or bloodstream. The main goal of the study was to test whether probiotics can directly degrade cholesterol as well as produce metabolites that interfere with its synthesis in the liver. The effect may also be partially ascribed to an enzymatic deconjugation of bile acids.