The human gut microbiome plays a vital role in aiding digestion, regulating host immunity, metabolism, protecting against pathogens and overall health1. In children, the development of the gut microbiome over the first two to three years of life is crucial, acting as a critical period that shapes lifelong health outcomes2. Despite its importance, our understanding of how the gut microbiome evolves in infancy and its implications for future health remains incomplete.

Developmental gut microbiome research has often relied on small-scale or cross-sectional studies, limiting our ability to track microbiota changes over time or predict their impact on future health outcomes. The work from Hickman and colleagues uses 16S rRNA gene sequencing and longitudinal statistical modelling to predict early microbiota development trajectories and link them to health outcomes over the first 5 years of life.