Clinical Nutritionist CCN Exam Prep

Answer: D - The primary immunoglobulin in human breast milk is secretory IgA, which protects the infant gastrointestinal tract from infection caused by many pathogens. Beta lymphocytes are produced by the bone marrow and provide humoral immunity, while IgM antibody is involved in allergic response to antigens. Iron-binding lactoferrin is a protein which slows the growth of bacteria in the infant gut; its action is secondary to that of secretory IgA.