The term “supraorganism” (which we prefer to the more common but slightly less informative “superorganism”) refers to a collection of individuals which behave as a single unit with enhanced function. It was originally applied to groups of genetically-identical individuals such as social insect colonies (Moritz and Fuchs, 1998), but has since been expanded to include systems comprised of taxonomically-diverse species from all domains of life, as well as viruses (Salvucci, 2012). The human intestine plays host to up to 1014 bacteria, which outnumber the host's own cells by around an order of magnitude: microbial concentrations in the colon can reach 1012 cells per gram. There are also large numbers of viruses, predominantly bacteriophages, with at least 109 viral particles present per gram of human feces. Current evidence presents a picture of prevailing homoeostasis between host, microbiome and virome consistent with the description of a supraorganism, which can nevertheless enter a disrupted alternative state termed “dysbiosis.” Here we review this evidence and the potential for the adoption of supra-organismal approaches toward the treatment and prevention of dysbiosis in the future.
- GI tract