Gut microbiome
Etymology
A compound of “gut” (Old English “guttas,” the bowels) and “microbiome,” from Greek “mikros” (small) and “bios” (life). The word “microbiome” was popularized in the early 2000s, often credited to the geneticist Joshua Lederberg, though the term had appeared earlier. Its rise marks a shift in thinking — from seeing microbes only as germs to seeing them as a resident organ.
noun phrase · /GUHT MY-kroh-byohm/
The vast community of bacteria and other microbes living in the digestive tract, and their collective genetic makeup.
What it names
The trillions of organisms we carry as a functioning part of ourselves — a hidden ecosystem now linked to digestion, immunity, and even mood.
Example
The doctor warned that a long course of antibiotics could disrupt his gut microbiome for months afterward.
Related idea
The gut microbiome is the community of resident microbes; a bacteria is a single such organism, and not all of them are harmful. The concept reframes the body as an ecosystem rather than a fortress — many of its bacteria are not invaders to repel but partners to protect.