The National Academies of Sciences, Engineering, and Medicine have released a new report that proposes a research strategy to advance understanding of the interactions between environmental chemicals and the human microbiome and the implications of those interactions on human health risk. The report also highlights key aspects of the human microbiome and its relation to health, describes potential interactions between environmental chemicals and the human microbiome, reviews the risk-assessment framework and reasons for incorporating the proposed research, describes methods for studying the microbiome, and identifies barriers for research and opportunities for collaboration.