A landmark study by the Salk Institute and collaborators illuminated the critical role of the gut microbiome’s composition and function in pediatric undernutrition and growth stunting. Analysis of toddlers in Malawi revealed that an unstable microbiome correlates with poor nutrient absorption and impaired growth outcomes. The research suggests that targeting microbiome health early in life could become a strategic pillar to prevent malnutrition, a major global health challenge.