Dynamics of gut metabolome and microbiota maturation during early life

Early-life gut microbiome-metabolome crosstalk plays a crucial role in maintaining host physiology. The microbially produced metabolites often convey effects on host health and physiology. This study investigates the gut metabolites, including short-chain fatty acids (SCFAs), bile acids (BAs), and polar metabolites, and their relationship to gut microbiota composition in a birth cohort of 670 children. Samples were collected at 2.5 (n = 272), 6 (n = 232), 14 (n = 289), and 30 months (n = 157) of age. We identified the trajectories of the fecal metabolome that relate to the maturation of the early-life gut microbiota. We found that prevalent gut microbial abundances were associated with microbial metabolite levels, particularly in 2.5-month-old infants. Here, the abundances of early colonizers, e.g., Bacteroides, Escherichia, and Bifidobacterium, were associated with microbial metabolites, especially secondary BAs, particularly in breastfed infants. Our results suggest that early-life gut microbiota associates with changes in metabolome composition, particularly BAs, which may have physiological implications.