The study, from researchers at Harvard T.H. Chan School of Public Health, Broad Institute of MIT and Harvard, and University of Maryland School of Medicine, presents a three-fold expansion of data from the National Institutes of Health Human Microbiome Project, providing unprecedented depth and detail about human microbial diversity. The new information allows researchers to identify differences that are unique to an individual's microbes-just like some human genome variants are unique to each individual-and track them across the body and over time. "This study has given us the most detailed information to date about exactly which microbes and molecular processes help to maintain health in the human microbiome," said Curtis Huttenhower, associate professor of computational biology and bioinformatics at Harvard Chan School, associate member of the Broad Institute, and senior author of the study.