Physiological immaturity of the enterohepatic circulation of bile acids

Biliary flow is directly dependent upon the adequate synthesis, conjugation, secretion, and recirculation of bile acids1–3. Efficient transport of bile acids is central to the biliary elimination of many endogenous and exogenous compounds since they are the main determinants of bile flow in the mature animal4. At birth the newborn can no longer depend upon placental excretory function, and during the transition from fetal to an extrauterine existence progressive maturation of the liver and gastrointestinal tract must occur. Inefficiency of normal physiological events such as bile secretion and fat digestion are the consequences of faulty adaptation to these new demands5,6.