Astrocytes are the most abundant type of cells within the central nervous system (CNS), but they remain poorly characterized. Researchers have long assumed that astrocytes’ primary function is to provide nutrients and support for the brain’s more closely scrutinized nerve cells; over the years, however, increasing evidence has shown that astrocytes can also actively promote neurodegeneration, inflammation, and neurological diseases. Now, a team led by researchers from Brigham and Women’s Hospital, has shown that a specific astrocyte sub-population can do the opposite, instead serving a protective, anti-inflammatory function within the brain based on signals regulated by the bacteria that reside in the gut. Findings on the new anti-inflammation pathway are published in Nature.