Explain why the production and entero-hepatic circulation of bile acids is of key importance in regulating the concentration of serum LDL-cholesterol, and to LDL-lowering treatments

Topic: With reference to the digestion of fat and LDL receptors, explain why the production and entero-hepatic circulation of bile acids is of key importance in regulating the concentration of serum LDL-cholesterol, and to LDL-lowering treatments (max 750 word)