URBANA, Ill. – Nearly every American who has become a parent in the last decade has heard the slogan, “breast milk is best,” and has likely been encouraged to offer breast milk to newborns. Among other things, breast milk contains natural sources of prebiotics: small, indigestible fiber molecules that promote the growth of good bacteria in the baby’s gut. Yet for many families, breastfeeding is difficult or impossible. Fortunately, modern infant formulas are getting closer to the real thing with the help of University of Illinois researchers.