The human gut microbiome is a complex microbial ecosystem that develops rapidly during early life and is shaped by interactions between microbial species, environmental exposures, and mobile genetic elements. Plasmids can contribute to these interactions by transferring adaptive traits between bacterial hosts; however, the distribution, persistence, and ecological roles of plasmid-mediated genes within the developing gut microbiome remain poorly understood. This project will use longitudinal metagenomic data from early-life microbiome cohorts to investigate plasmid-mediated microbial interactions and their contribution to microbiome development. Computational analyses will include metagenomic assembly, identification and reconstruction of plasmids, prediction of bacterial hosts, and functional annotation of plasmid-associated genes. Longitudinal and statistical analyses will then be used to examine the persistence and transmission of plasmids and associated traits across individuals and time points, and to investigate their relationships with microbial community composition and development. The project will generate large-scale genomic and metagenomic datasets and requires high-performance computing for sequence processing, assembly, annotation, comparative genomics, and downstream statistical analyses.