Hippocrates wrote “let food be thy medicine.” Although access to nourishing food seems to be an obvious solution to the global health crisis of childhood undernutrition, the solution is not simple from a social or metabolic perspective, or even from the perspective of a microbiologist. To effectively address childhood undernutrition, clinicians need to be mindful that both our human and microbial selves need specific nourishment to restore and maintain healthy development and growth. The laboratory of Dr. Jeffrey Gordon has provided fundamental insight into what constitutes healthy microbiota in children from across the world1,2 and has shown that in moderate . . .