Gut bacteria that prevent growth impairments transmitted by microbiota from malnourished children

TLDR

Undernourished children have underdeveloped gut microbiota. Transplanting microbiota from healthy or undernourished Malawian infants into germ‑free mice on a Malawian diet showed that immature microbiota causes growth deficits, but cohousing or adding invasive species Ruminococcus gnavus and Clostridium symbiosum can prevent these impairments. The abundance of age‑discriminatory taxa in mice correlated with lean mass, metabolic function, and bone structure, supporting a causal link between microbiota immaturity and undernutrition and highlighting therapeutic targets.

Abstract

Undernourished children exhibit impaired development of their gut microbiota. Transplanting microbiota from 6- and 18-month-old healthy or undernourished Malawian donors into young germ-free mice that were fed a Malawian diet revealed that immature microbiota from undernourished infants and children transmit impaired growth phenotypes. The representation of several age-discriminatory taxa in recipient animals correlated with lean body mass gain; liver, muscle, and brain metabolism; and bone morphology. Mice were cohoused shortly after receiving microbiota from healthy or severely stunted and underweight infants; age- and growth-discriminatory taxa from the microbiota of the former were able to invade that of the latter, which prevented growth impairments in recipient animals. Adding two invasive species, Ruminococcus gnavus and Clostridium symbiosum, to the microbiota from undernourished donors also ameliorated growth and metabolic abnormalities in recipient animals. These results provide evidence that microbiota immaturity is causally related to undernutrition and reveal potential therapeutic targets and agents.