Intestinal microbiota are critical for health with changes associated with diverse
human diseases. Research suggests that altered intestinal microbiota can profoundly
affect brain function. However, whether altering brain function directly affects the
microbiota is unknown. Since it is currently unclear how brain injury induces clinical
complications such as infections or paralytic ileus, key contributors to prolonged
hospitalization and death post-stroke, we tested in mice the hypothesis that brain
damage induced changes in the intestinal microbiota. Experimental stroke altered the
composition of caecal microbiota, with specific changes in Peptococcaceae and Prevotellaceae
correlating with the extent of injury. These effects are mediated by noradrenaline
release from the autonomic nervous system with altered caecal mucoprotein production
and goblet cell numbers. Traumatic brain injury also caused changes in the gut microbiota,
confirming brain injury effects gut microbiota. Changes in intestinal microbiota after
brain injury may affect recovery and treatment of patients should appreciate such
changes.
