To Dr. Jack's list I would add that a breastfed baby has a NORMAL immune
system, which is good at fighting off infections, while a bottle/formula-fed
baby has an abnormal immune system which is not as good at fighting off
infections.

In the anecdotal category, my youngest had three unilateral ear infections,
all on the side that was "up" when he nursed (he only liked to nurse from my
right breast, lying on his left side, and the infections were all in his
right ear).  This suggests that breast milk in the ear canals kills bacteria.

Kathy Dettwyler