As Kathryn Whitehead breastfed her daughter, she would ponder and she would plan.
At a basic level, the chemical engineer knew the breast milk she was giving her infant was chockfull of immune cells, antibodies, enzymes, hormones, and other such substances that promoted health and warded off disease. The stuff, after all, was sometimes referred to as “liquid gold.”
But what Whitehead didn’t know — and what scientists in general still don’t know — is why, precisely, breast milk is so healthful. It made her wonder: If she could come up with answers, might it be used to develop new therapeutics? “We could engineer cells to confer immunity to a baby, or to tolerize a baby to different allergens,” as Whitehead put it.