“A microbiota is an “ecological community of commensal, symbiotic and pathogenic microorganisms” found in and on all multicellular organisms studied to date from plants to animals. A microbiota includes bacteria, archaea, protists, fungi, and viruses. Microbiota has been found to be crucial for immunologic, hormonal and metabolic homeostasis of their host. The synonymous term microbiome describes either the collective genomes of the microorganisms that reside in an environmental niche or the microorganisms themselves. The microbiome and host emerged during evolution as a synergistic unit from epigenetics and genetic characteristics, sometimes collectively referred to as a holobiont.
All plants and animals, from protists to humans, live in close association with microbial organisms (see for example the human microbiome). Up until relatively recently, however, biologists have defined the interactions of plants and animals with the microbial world mostly in the context of disease states and of a relatively small number of symbiotic case studies. Organisms do not live in isolation but have evolved in the context of complex communities. A number of advances have driven a change in the perception of microbiomes, including:
- The ability to perform genomic and gene expression analyses of single cells and even of entire microbial communities in the new disciplines of metagenomics and metatranscriptomics.
- massive databases making this information accessible to researchers across multiple disciplines.
- methods of mathematical analysis that help researchers to make sense of complex data sets.
Increasingly, biologists have come to appreciate that microbes make up an important part of an organism’s phenotype, far beyond the occasional symbiotic case study.” https://en.wikipedia.org/wiki/Microbiota