Breast milk
jaundice has been reported to be associated with increased
lipase activity and elevated
free fatty acid (FFA) concentrations within breast milk. We have previously shown that
bile salts are present in small concentrations in breast milk and the aim of this study was to examine the relationship of
bile salt-stimulated lipase (BSSL) activity, FFA concentration, and
bile salt concentration in milks of normal infants and the milk of infants with breast milk
jaundice. Mothers of healthy newborn infants were recruited in the early newborn period and 42 provided breast milk samples at 2 weeks, 30 at 6 weeks, 16
at 10 weeks, and 13 at 14 weeks postnatally. We initially studied the effect of lactation on
bile salts and found there was a significant decline in both
cholate and
chenodeoxycholate levels with duration of lactation (p less than 0.05). There was also a significant fall in BSSL activity with duration of lactation (p less than 0.05), but no correlation was found between BSSL activity and
bile salt concentration. FFA concentrations were similar throughout lactation and were not related to either BSSL activity or
bile salt concentration. There was a significant increase in the concentration of
cholate and the
cholate-to-
chenodeoxycholate ratio in the milks of 12 infants with breast milk
jaundice compared with normal milks, the BSSL activity was similar and contrary to previous reports, the FFA concentration was not increased in the milks of infants with breast milk
jaundice.