The community of microorganisms associated with a particular site, e.g. a host organism or a habitat. The high-throughput techniques of metagenomics now enable rapid characterization and analysis of entire microbiomes, which is transforming knowledge of their constituents’ significance, whether as symbionts, commensals, or pathogens. For example, it is estimated that the human body has ten times as many microbial cells as body cells. Most of these have not been identified. Hence the establishment of the Human Microbiome Project, the aim of which is to characterize microbial communities found at various sites in the human body and correlate changes in the microbiome with human health. The Earth Microbiome Project, founded in 2010, is a collaborative effort using crowd-sourced samples to characterize microbial life on earth. See also holobiont.

https://hmpdacc.org/ NIH Human Microbiome Project