There is no doubt that the gut is sensitive to emotion. Many are familiar with “butterflies” in your stomach or loose stool with anxiety. Well, research reveals just how the gut-brain connection influences our emotional response.
It makes sense that the brain has direct influence over the gut. The brain is the master control, which sends signals to the digestive tract through our autonomic nervous system to enhance overall function and optimize nutrient breakdown and absorption. This includes the secretion of stomach acid, motility of the gut and blood flow to the digestive tract, controlled by the vagus nerve and glandular/hormonal output. 
During stress these signals get disrupted. The body diverts energy away from digestive function and increases adrenalin, which directs circulation towards the heart and muscles to “fight or flight”. Chronically, this wreaks havoc on your digestion. Many experience heartburn, bloating, gas, reduced appetite, constipation or diarrhea and overall poor digestion, many symptoms that mimic IBS.
In those with IBS, the gut-brain signals become disrupted. Those with diarrhea-predominant IBS are shown to have a heightened autonomic and stress response, also known as hyper-
responsiveness of the autonomic nervous system. Interestingly, those with constipation-predominant IBS present with a significantly lower autonomic response of the vagus nerve.
Stress, anxiety, depression and stressful life events are some of the most significant risk factors for the development of IBS. Infection can lead to physical stress on the body, in fact, recent meta-analysis demonstrates a six fold increase in the risk of developing IBS after an intestinal infection, which remains elevated up to two to three years post infection.[5,6]
As it turns out, the communication between the gut and the brain is a two way street. The gut, which is also called the second brain, influences the brain’s emotional response, including the release of stress hormones (cortisol and CRH). Research shows that those who suffer from digestive complaints are at a higher risk of mental health complaints, such as depression and anxiety.
To add another layer to the story, emerging data shows how the gut microbiome affects brain signalling. Changes within the gut bacteria are shown to influence pain perception in those with IBS by influencing inflammation, the stress response, immune function and areas in the brain that process emotions, called the amygdala. These bacteria are shown to produce a number of gut hormones, short chained fatty acids (SCFAs), and neurometabolites (GABA, norepinephrine, dopamine), which modulate the function of the nervous system and overall mood.[8,9]
Probiotics are now being used to alter psychological stress and improve pain sensitivity in those with IBS. These products have such a strong effect on the brain that some studies show the use of probiotics to improve mood significantly in those with mild to moderate depression.
Don’t guess, assess! Find out through objective functional testing to see the underlying mechanism of your symptoms.
Based on these findings it is imperative that the relationship between the gut and the brain be addressed during treatment. For those who suffer from mental health disorders, improving gut
function while reducing autonomic stimulation (the stress response) can be an effective approach to modulate the nervous system to find relief from anxiety, insomnia and depression.
In addition, addressing gut concerns can optimize your digestion and absorption of neutraceuticals and foods, which contain essential nutrients to improve your recovery and repair.
On the other end of the spectrum, it is important to address the balance of the nervous system when digestive symptoms are present. Alterations in the autonomic nervous system can not only
affect functional gut disturbances, but hormone, immune, cardiovascular, detoxification and reproductive systems as well.
Physical signs of stress: 
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In best of health,
Dr. Robyn Murphy, ND
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