Serum levels of bile salt-stimulated lipase and breast feeding.

Objectives: Bile salt-stimulated lipase (BSSL) is present in the sera of healthy humans, may affect lipoprotein structure and composition, and reduce atherogenicity of oxidized LDL-cholesterol. Our aims were to examine serum levels of BSSL in breast- and formula-fed infants, and explore the influence of BSSL on serum lipid profile and oxidative status.

Methods: Infants (2-8 weeks old) were prospectively enrolled. Blood was drawn for serum levels of BSSL, total antioxidant status (TAS), and lipid profile.

Results: Serum levels of BSSL were similar in breast-fed (0.28 +/- 0.15 microg/l, n = 18) and formula-fed (0.31 +/- 0.09 microg/l, n = 15) infants, and were much lower than reported levels for adults. In breast-fed infants only, BSSL levels were correlated with LDL-cholesterol serum levels (r = -0.53, p = 0.04). Total cholesterol (119.2 +/- 34.3 mg/dl vs 97 +/- 27.2, and p = 0.05) and LDL-cholesterol serum levels (50.5 +/- 26.1 mg/dl vs 33.3 +/- 20.3, p = 0.05), were elevated in breast-fed compared with formula-fed infants, but TAS was similar in both groups (1.02 +/- 0.18 mmol/l and 0.98 +/- 0.12 mmol/l, respectively).

Conclusions: Lack of difference in BSSL serum levels between formula- and breast-feeding, and lower BSSL levels in infants compared to adults, suggest that human milk does not contribute to BSSL serum levels.