"Doctors have long known that infants who are breast-fed contract fewer
infections than do those who are given formula. . . . Several molecules
in human milk besides secretory IgA prevent microbes from attaching to
mucosal surfaces. Oligosaccharides, which are simple chains of sugars,
often contain domains that resemble the binding sites through which
bacteria gain entry into the cells lining the intestinal tract. Thus,
these sugars can intercept bacteria, forming harmless complexes that the
baby excretes. In addition, human milk contains large molecules called
mucins that include a great deal of protein and carbohydrate. They, too,
are capable of adhering to bacteria and viruses and eliminating them from
the body.
"The molecules in milk have other valuable functions as well. Each
molecule of a protein called lactoferrin, for example, can bind to two
atoms of iron" (Newman 76, 78).
