Microbial consortium

A microbial consortium or consortium, is two or more bacterial or microbial groups living symbiotically. Consortiums can be endosymbiotic or ectosymbiotic, or occasionally may be both. The protist "Mixotricha paradoxa", itself an endosymbiont of the "Mastotermes darwiniensis" termite, is always found as a consortium of at least one endosymbiotic coccus, multiple ectosymbiotic species of flagellate or ciliate bacteria, and at least one species of helical "Treponema" bacteria that forms the basis of "Mixotricha" protists' locomotion.
The concept of a consortium was first introduced by Johannes Reinke in 1872, and in 1877 the term symbiosis was introduced and later expanded on.
Human Health.
Consortia are commonly found in humans, with the predominant examples being the skin consortium and the intestinal consortium which provide protection and aid in human nutrition. Additionally, bacteria have been identified as existing within the brain (previously believed to be sterile), with metagenomic evidence suggesting the species found may be enteric in origin. As the species found appear to be well-established, have no discernible impact on human health, and are species known to form consortia when found in the gut, it is highly likely they have also formed a symbiotic consortium within the brain.