Welcome to the quantum science podcast.

Each episode, we bring you stories about developments in science and mathematics.

I'm Susan Vallett.

Bacteria are in, around, and all over us.

They thrive in almost every corner of the planet, from deep

sea hydrothermal vents to high up in the clouds, to the crevices of our ears, mouth,

nose, and gut. But scientists have long assumed that bacteria can't survive in

the human brain. But can they? That's next.

Quantum Magazine is an editorially independent online publication

supported by the Simon's Foundation

to enhance public understanding of science.

The thinking goes that the powerful blood-brain barrier keeps the brain mostly free from outside invaders. But are we sure that a healthy human brain doesn't

have a microbiome of its own? Over the last decade, initial studies have

presented conflicting evidence. The idea has remained controversial. After all, it's hard to obtain

healthy, uncontaminated human brain tissue that could be used to study possible microbial

inhabitants. Recently, a study published in science advances provided the

strongest evidence yet that a brain microbiome can and does exist in healthy vertebrates,

at least in fish. Researchers at the University of New Mexico discovered communities of bacteria

thriving in salmon and trout brains. Many of the microbial species

have special adaptations that allow them to survive in brain tissue, as well as techniques

to cross the protective blood-brain barrier. Matthew Ome is a physiologist who studies the human

microbiome at the University of Colorado Boulder and wasn't

...