Many of my patients come to see me for digestive health, so why on earth would I ask them about past head injuries? Here's why:
Brain injuries affect the microbiome!
As I was nerding out in my free time, I came across a 2018 research review on TBIs - traumatic brain injuries - and their effect on immunity, inflammation, and the gut microbiome.
Most of this research is hot off the press, and what is shown is that brain injuries start a cascade of events within 2 hours of the TBI occurrence and many affect the gut.
First - autonomic changes occur, this means a change in our nervous system. Makes sense because we've got so many nerves that begin in our head. The one most important to our digestive tract is the vagus nerve.
When the vagus nerve is damaged, the nervous system is heightened to have more stress (aka sympathetic response), which can influence gut motility, leaky gut, and the microbiome.
Second - the nervous system imbalance radiates throughout the entire body and is perceived as added stress. The body responds with increases stress hormones, called catecholamines.
Third - the leaky gut expresses itself more by decreasing tightness of intestinal tight junctions. These are cells are responsible for keeping the gut impermeable. When they are leaky, this can cause inflammation in the digestive tract, which causes abdominal pain, bloating, and changes in the microbiome.
Fourth - TBIs can lead cause nerve cells to die and can disrupt the blood-brain barrier. This in turn activates inflammatory cells, called cytokines, which circulate throughout the body and trigger changes in the gut.
Research on the gut-brain axis continues to reveal itself, and a traumatic brain injury affecting the gut is yet another example. If you've had a TBI and have digestive symptoms, that is a very helpful thing for your doctor to know.
There are many treatments available to help reset the nervous system and the digestive system with a little help from your healthcare provider. As always, feel free to drop me a line for more information on digestive health!