Not so-sterile brains? Researchers find harmless bacteria living there

In the latest example of bacteria being “literally everywhere,” scientists appear to have found evidence of microbes living harmlessly in our brains.

…

[The] researchers looked at high-resolution images of slices of postmortem human brain tissue, where they found signs of bacteria, according to Science Magazine.

…

“The brain has always been thought of as a sterile site,” said Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security in Baltimore, who was not involved in the study. “To find [bacteria] there doing no harm sort of breaks a lot of the dogma” on this.

..

[T]he researchers analyzed samples from 34 postmortem analyses of human brains and found bacteria in every brain. Importantly, the researchers found no signs of inflammation or bacterial disease in the brains they examined.

The bacteria seem to prefer certain parts of the brain, as the microbes tended to cluster in areas known as the hippocampus, prefrontal cortex and substantia nigra, according to the study abstract. And often, the bacteria were found in star-shaped brain cells known as astrocytes that were near the blood-brain barrier.

When the researchers sequenced genetic material from the bacteria, they found that most of the microbes were from groups of bacteria that are typically found in the human gut, known as Firmicutes, Proteobacteria and Bacteroidetes.

Read full, original post: Bacteria May Live (Harmlessly) in Your Brain