Page 434 - Total War on PTSD

into the microbes within our microbiome to isolate specific ones that might correlate with certain diseases.
They do know that the microbiome-gut-brain axis is a circular process and can be impacted at either end, resulting in a variety of interesting hypotheses; it is bi- directional. Therefore changes in attitude and mental states may affect the microbiome, just as the microbiome affects our psychological condition.
There are billions of microbes in the gastrointestinal tract. We once assumed that the blood-brain barrier limited access to the brain. Now we know that bacteria in the gut create metabolites that can circulate across the barrier. According to Bergland (2016) we understand that the barrier is penetrable and the brain is highly impacted by microbes from the gut: the pathways are achieved through blood flow and through the vagus nerve, known as the “wandering nerve”, the longest cranial nerve that travels from the brain stem through the neck and into the chest and abdomen, enervating the heart, major blood vessels, airways, lungs, esophagus, stomach and intestines. It controls the parasympathetic part of the nervous system that regulates among other things our ability to “rest and digest” as opposed to the sympathetic which drives the “fight-or-flight” response (Bergland, 2016).
So you can see how this intertwined system cannot be separated into fragments. An overly aroused system of fight-flight responses and accompanying neurotransmitter activity is now seen as stimulating systemic inflammatory responses that are indicated in chronic pain responses (Bergland, 2016). OK, you get the picture of these profound connections: the revolving door of “mental states” becoming “physical states," and back around, while deeply embedded in our nervous system, influencing our
434 of 1085