MILK-BORNE BIOACTIVE PEPTIDES

Milk is now known to contain an array of bioactivities which extends t he range of influence of mother over young beyond nutrition alone. Bio activities in milk include modulators of digestive and gastrointestina l (GI) functions, hemodynamics (GI blood flow, hypertension), along wi th hormones and growth factors (mammary or infant development) probiot ic microbial growth control, immunoregulation, nonimmune disease defen se. Many milk borne bioactivities are latent, requiring proteolytic re lease of bioactive peptides from inactive native milk proteins, and th erefore depend on protease activitiy at a target tissue site such as t he GI tract of the suckling. Several bioactivities of milk involve int eraction of peptide or protein and non-peptide components of milk, and are kinetically dependent on the time available for action and the co ncentration of reactants. Hence, factors which alter the kinetic envir onment within the GI tract may indirectly but profoundly influence ove rall milk bioactivities within the GI tract of the suckling. (C) 1998 Elsevier Science Ltd. All rights reserved.