The Gut-Brain Axis

July 2, 2013

The function of our brain directly affects the function of our gut, and vice versa.  This is a continuous cycle, unless each of the components is addressed appropriately and in concert (if it is determined that both are involved).   Inadequate brain function, whether it be the result of abnormal brain maturation (such as with disorders that occur due to abnormal development, like Autism, ADHD, learning disabilities, etc.), brain injury (post-stroke, traumatic injury such as from a blow to the head or concussion), inappropriate stimulation (due to spinal injury or biomechanical abnormalities affecting feedback-feedforward mechanisms from the spine to the brain and the brain to the spine).  When the brain is not forming the correct connections in order to control the autonomic nervous system (which controls the digestive, cardiovascular, respiratory, cutaneous systems) there are effects in the function of these systems.  The most common is the effect on the gut (small/large intestine) including the integrity of the intestinal wall cellular structure, the balance of gut flora, the vascular supply to these organs for proper function, and the control over smooth muscle tone that is required for contraction and relaxation of the intestines thereby allowing for the movement of food particles through the system in order to break them down.  In addition to this, is the effect on the pH of the stomach which is required to be at the proper level to breakdown certain foods, and produce one of the important neurotransmitters for our brain, serotonin.

When there is a compromise in the gut barrier, undigested food particles and other antigens can get through the intestinal wall into the submucosa and from there into the blood stream, activating an immune and pro-inflammatory response.  This creates further compromise in the integrity of the intestinal wall barrier, allowing for more of these particles to get through and driving the pro-inflammatory response over and over again.  Compromise in the vascular system, can eventually lead to compromise in the blood-brain-barrier, which is intended to protect our brain from outside effects. If these pro-inflammatory cytokines reach our blood-brain-barrier they begin to compromise the brain cells and this can lead to serious neurological conditions. 

Many auto-immune conditions are closely linked to a problem in brain function and in the gut-brain axis.