Microbiotas from extremely preterm infants with growth faltering impair postnatal growth and metabolism in mice.

Postnatal growth faltering is a pervasive problem among extremely preterm infants that is independently associated with adverse neurodevelopmental outcomes. We previously observed that preterm infants with poor postnatal growth have altered development of the intestinal microbiota relative to preterm infants with appropriate postnatal growth. Here, we used gnotobiotic mice to investigate whether these differences in microbiota development independently contribute to growth faltering. We found that colonization of neonatal mice with microbiotas from extremely preterm infants with poor growth reproduced postnatal growth impairment and induced a metabolic signature of enhanced lipolysis and fatty acid oxidation in the mice, characterized by elevated hepatic acylcarnitines and circulating ketones. In mice colonized at birth with microbiotas from infants with poor growth, postnatal treatment with microbiotas from infants with appropriate growth prevented growth impairment. These results indicate that altered development of the intestinal microbiota contributes to growth faltering in extremely preterm infants and that microbiota modification can restore postnatal growth.