∞ generated and posted on 2017.08.25 ∞

Those microorganisms found in association with a given environment and particularly from the perspective of what genes they carry as well as what impact they have.

Originally the concept of a Microbiome was derived from the idea of metagenomics of the microbial biome associated with specific loctations, especially individual organisms. The concept, however, has broadened to include not just the genes associated with those organisms but also to the constituting organisms themselves. Still, the primary means by which Microbiomes are characterized is via metagenomics.

The idea of a microbiome is quite similar to that of normal flora a predominant difference being the phenotypic (or ecological considerations of normal flora versus the more genomic (and therefore genotypic) emphasis of the idea of a microbiome.

There also is a greater community emphasis in considering microbiomes (multiple microbial species) versus a more population emphasis (individual microbial species) with regard to normal flora.

That is, the totality of the impact of microorganisms on specific environments, including ourselves, rather than the impact (or relative lack thereof) of individual bacterial species or individuals strains on those environments.

Indeed, there also are more subtle considerations regarding heath when describing microbiomes versus normal flora, a distinction that may simply reflect the genotypic emphasis of microbiomes, where genotype, today, is a more tractable quantity (in terms of DNA sequencing). Therefore one which could potentially identify greater subtleties versus more traditional (and phenotype-based) microbiological techniques.

The idea of microbiomes also explicitly considers the sophistication of the interactions between the genomes of macroorganisms and those of microorganisms, where a microbiome is considered to be both an inherited quantity and the product of potentially millions of years of coevolution.

Indeed, our microbiome can be considered to be somewhat distinct tissues making up our bodies, "tissues" which exist in addition to the standard tissues – consisting of human cells – that traditionally have been considered to be what makes up our bodies. One must keep in mind, though, that microbiomes are associated not just with animals but also plants, fungi, and, indeed, environments generally.

See also dysbiosis and fecal transplantation.