Almost 180 million children across the globe are stunted, a severe, disabling consequence of malnutrition, repeated childhood infections, and sometimes irreversible damage. Now, new studies suggest the gut microbiome plays a critical role in infant growth—sometimes promoting it even in the absence of sufficient calories—providing tantalizing, if preliminary, clues about possible new interventions.

Human gut microbes can be transplanted effectively into germ-free mice to recapitulate their associated phenotypes. Using this model, researchers found that the microbiota of healthy children relieved the harmful effects on growth caused by the microbiota of malnourished children.

They show that microbial communities change as an infant ages, and when they don't poor nutrition leads to stunting and other problems.

Work in germ-free mice shows providing the right human microbial communities can restore growth, likely by restoring the proper connections between growth hormone and insulin like growth factor 1. And supplying young mice with certain sugars typically provided in breast milk helps to make sure the right microbial community gets established.

Together these studies reveal that specific beneficial microbes could potentially be exploited to resolve undernutrition syndromes.

http://science.sciencemag.org/content/351/6275/aad3311