Microbes are ‘unknown unknowns’ despite being vital to all life, says study

Understanding these tiny organisms could be crucial to tackling threats such as coronavirus, but new research shows how little we know

A human tongue with each colour representing a different type of microbe. Microbes in humans are linked to conditions from obesity and diabetes to anxiety. Photograph: Tabita Ramirez-Puebla and Jessica Mark Welch/Marine Biological Laboratory

A new study has highlighted how little is known about microbes – the hidden majority of life on Earth.

Life on the planet relies on an enormous quantity of bacteria, fungi and other tiny organisms. They generate oxygen, keep soils healthy and regulate the climate. Microbes play a crucial role in food production, such as cheese, beer, yoghurt and bread.

But despite their importance to human life and the health of the Earth, a new scientific paper has shown our “profound ignorance” of microbial biodiversity and how it is changing.

“We have no idea whether global microbial diversity is increasing, decreasing, or staying the same,” said David Thaler, a biologist at Basel University and author of the paper. “Most scientific papers tell us new facts. This is a different kind of paper; it does not answer anything but asks a new question.”