Gut microbiota response to malnutrition

Childhood malnutrition is a major health problem in many low-income countries, and although mortality can be reduced by therapeutic food interventions, it is difficult to achieve complete restoration of healthy growth in cases of severe acute malnutrition. Here Jeffrey Gordon and colleagues identify a group of 24 bacterial species whose proportional representation in the microbiota defines how a healthy microbiota assembles over the course of the first two postnatal years in a cohort of healthy children in Bangladesh. They define a 'relative microbiota maturity index' and 'microbiota-for-age Z-score' that allow comparison across individuals and use these indices to demonstrate that severe malnutrition is associated with significant relative microbiota immaturity that is only partially ameliorated by two widely used nutritional interventions. This work suggests that more prolonged food-based interventions and/or addition of gut microbes may be needed to achieve durable repair of microbiota immaturity in childhood malnutrition and improved clinical outcomes.