microorganisms

Cultural  

1. Organisms so small that they can be seen only through a microscope. (See bacteria, protozoa, and viruses.)

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Example Sentences

Allen had a test run on her infant’s gut microbiome—the collection of bacteria and other microorganisms that inhabit the digestive tract.

From The Wall Street Journal • Mar. 3, 2026

When lake levels are high, microorganisms more effectively consume methane before it can reach the atmosphere.

From Science Daily • Feb. 24, 2026

"At higher temperatures, microorganisms break down organic material faster, and both CO2 and methane emissions rise," says Zhao.

From Science Daily • Feb. 22, 2026

Some trials show that the sweeteners can raise blood sugar, weaken blood-sugar control and cause dysfunction in the gut microbiome, the collection of bacteria and other microorganisms in the gut.

From The Wall Street Journal • Jan. 23, 2026

However, there are many other possibilities, ranging from large plants and animals to microorganisms, to extinct forms, to a planet that is now and was always lifeless.

From "Cosmos" by Carl Sagan