Bile salt-stimulated lipase in human milk from 2 to 16 weeks postpartum.

Our objectives were to determine the change in bile salt-stimulated lipase (BSSL) activity in mature milk with time postpartum and to determine if BSSL activity was related to total lipid in the milk. Milk samples were collected from 12 mothers at 2, 6, 12 and 16 weeks postpartum. A significant (P less than .05) decrease in BSSL activity with time was observed. The average values expressed as mumol free fatty acids released/min/ml milk were 5.3, 4.5, 4.1 and 3.6 at 2, 6, 12 and 16 weeks postpartum. Total lipid in the milk increased significantly (P less than .05) from 4.1 g/dl at 2 weeks to 5.4 g/dl at 16 weeks postpartum but was not significantly correlated with BSSL activity.