Unveiling Developmental Trajectory in Infant Macaques: Insights from Longitudinal Multi-omics Studies and Comparative with Humans

The functional dynamics within the gut microbiota and host of infants remain poorly understood. Here, blood transcriptomes and fecal metagenomes were sequenced from 21 rhesus macaques ( Macaca mulatta ) infants at seven distinct time points over a 468-day period (6–22 months of age) to trace gene expression patterns and gut microbiota maturation. We found functions of the “core” gut microbial community remained relatively stable, but there were fluctuations in the composition and abundance of gut microbiota. Alterations in the fecal metagenome were correlated with changes in diet and environment, while shifts in the blood transcriptome were indicative of developmental and immunological trends. The overall trend of the gut microbiota of both humans and macaques to reach adult-like configurations was comparable, albeit with notable differences in developmental trajectories. Our study emphasizes the potential utility of infant macaques as suitable models for human infant development, particularly with respect to gut microbial maturation.