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Cortisol and the Digestive System: Reciprocal Effects

An image of a person holding their stomach due to painful indigestionAny time you experience stress, the ‘fight or flight’ syndrome becomes activated. You get prepared to either fight against the stressor or flee from it. The hypothalamic-pituitary-adrenal (HPA) axis sets in motion a cascade of biochemicals and hormones that end in the stimulation of your adrenal glands and the release of cortisol. This starts your body’s fight against the effects of stress. And not only does this stress hormone affect stress, but it also affects other parts of your body. The focus of this article concerns the reciprocal effects of cortisol and the digestive system.

The Role of Cortisol

During stressful experiences, especially chronic stress, the level of cortisol in your bloodstream increases significantly. As a result, negative impacts occur on many of the body’s systems, especially the digestive system.

Normally, cortisol plays a major role in your body’s nutritional needs. This makes up one factor involved in the relationship between cortisol and the digestive system. In order to meet the physical demands placed on it in a typical day, cortisol helps regulate energy by choosing the right combination of fats, carbohydrates, and protein. A chronic elevation of cortisol as seen in chronic stress brings negative effects on the immune system, weight, and risk of chronic illness conditions.

Yet another aspect of the relationship of cortisol and the digestive system involved biochemical and hormonal imbalances that come about as cortisol shifts your body’s functioning from everyday living to surviving. And this shift sets aside those processes that do not contribute to immediate survival. Therefore, digestion slows or stops altogether until the stress resolves.

However, in the fast-paced, stressful lifestyle many people lead, your adrenal glands continue releasing large amounts of cortisol. As a result, your whole body experiences an imbalance of hormones and your immune system suffers.

During the stress response, cortisol helps in redirecting blood flow from the digestive tract to the brain and large muscles. Therefore, digestion becomes suppressed when you experience stress. So, the constant experience of stress with its accompanying high levels of cortisol places a huge burden on your body due to stopping the digestive process.

Cortisol and the SNS

In addition to other aspects of the relationship of cortisol and the digestive system, cortisol triggers the sympathetic nervous system which activates the body more. And this triggering inhibits the parasympathetic nervous system which slows the body down because the two systems can’t operate at the same time. This leads to more digestive difficulty because relaxation plays an important role in how enzymes and hormones utilized in digestion and absorption work at their best.

Cortisol and the Digestive System: Reciprocal Impact

An image of a seated woman looking stressed outWhen stress becomes chronic your entire system floods with cortisol. So, when you eat and experience stress, a number of things take place.

For example, your digestive process and the absorption of nutrients become compromised. This leads to indigestion and irritation of the mucus lining of your gut. Inflammation increases due to this irritation which then leads to an increase in cortisol to fight the inflammation. This becomes a source of stress which impacts your already overburdened adrenal glands. And this cycle once again sets in motion a stress response. So, if you suffer from Adrenal Fatigue Syndrome (AFS) this fact exacerbates your condition by adding stress.

Stress typically affects your gut in one of two ways. Either it slows down the motility of your gut or speeds it up.

Slowing down your gut’s motility leads to constipation. As a result, your body can’t rid itself of waste. Consequently, bloating, gas, and/or stomach pain develop. If you suffer from any of several chronic gastrointestinal conditions such as irritable bowel syndrome, this constipation will exacerbate the condition. Likewise, it becomes another source of stress which places more burden on your adrenal glands to release cortisol. This becomes another part of the relationship between cortisol and the digestive system.

Speeding up your gut’s motility leads to diarrhea. Your food moves too fast through your digestive system. As a result, your ability to absorb nutrients decreases which can lead to nutrient deficiencies. If you don’t absorb sufficient nutrients, you can’t make enough energy for your body to function efficiently. In addition, since cortisol shunts blood from your digestive tract to your brain and muscles, the decrease in blood flow slows down your metabolism, leading to lower energy availability. This process shows another aspect of the relationship of cortisol and the digestive system.

Leaky Gut

In the same vein, stress and the accompanying high levels of cortisol negatively affect the permeability of the lining of your gut. Normally, the endothelial cells lining your gut only allow digested food particles and nutrients through them into the bloodstream. However, under chronic stress, the junctions between these cells loosen, allowing pathogens and other substances access to your bloodstream.

When this happens, your immune system becomes triggered to identify and destroy these foreign invaders and preserve your health. Inflammation is one result. And if the flood of pathogens through what is called ‘leaky gut’ becomes more than your immune system can easily handle, the immune system may become hyperactive. When this occurs, the immune system may misidentify healthy cells as invaders and begin attacking them. This sets in motion the development of autoimmune conditions. Such a process becomes one more example of the relationship between cortisol and digestive system problems.


Another way to see the relationship between cortisol and the digestive system come about by looking at the microbiome. Stress and the resulting high levels of cortisol directly affect the microbiome. Normally, the ‘good’ and ‘bad’ bacteria contained in the microbiome maintain a balance. However, under stress, this balance can become unstable due to the effects of the sympathetic nervous system that keeps your body stimulated and overactive. This can lead to a condition called small intestinal bacterial overgrowth or SIBO. The ‘bad’ bacteria increase dramatically, leak over into the gut, and further weaken the intestinal lining.

Enteric Nervous System

The enteric nervous system often called the ‘second brain’, resides in your gut. This leads to you feeling emotions in your gut. A part of the autonomic nervous system, the enteric nervous system contains more neurons than your spine and produces neurotransmitters such as dopamine, serotonin, and acetylcholine. These same neurotransmitters work in the brain to help regulate emotional responses.

About 95% of the serotonin used in your body occurs in the gut. This neurotransmitter plays an important role in depression. In addition, it triggers the stomach contractions you feel when you eat spoiled food and stimulates diarrhea and vomiting to expel dangerous food from your body.

The Gut-Brain Axis

In the same vein, your gut and brain interact with each other in a two-way fashion. When stress hits, it affects your brain in a number of ways just as it affects your gut. Therefore, this factor makes it important to address both your brain and your gut when a significant health issue such as stress affects one or the other.

People suffering from problems affecting the digestive tract often also experience mood disorders. Chronic stress provides a trigger for digestive conditions. And chronic stress means increased levels of cortisol which also can affect your brain negatively. This becomes yet another example of the relationship between cortisol and the digestive system.

Conclusions Regarding Cortisol and the Digestive System

Current research indicates a definite connection between cortisol and the digestive system. Stress increases the level of cortisol in your body to the point of negatively affecting every system in your body, especially the digestive system.

Blood flow decreases in your digestive system and increases in your brain and muscles. This fuels the fight or flight response.

Ordinarily, this procedure would reverse itself once the stress affecting you resolves. However, in this high-stress, fast-paced culture, chronic stress becomes the norm. This results in high levels of cortisol in your body over long periods of time. The high cortisol levels negatively affect not only digestion but also the absorption of nutrients.

If you suffer from AFS, the impact of high levels of cortisol on your digestive system increases. The resulting digestive issues become additional sources of stress on your body, leading to increased AFS symptoms.

What Can You Do?

If you are suffering from high cortisol that interferes with your digestive system, here are a few things you can do to alleviate the situation.

An image of healthy, probiotic foods in bowls that can help with inflammation

  1. Do all you can to reduce the amount of stress in your life
  2. Try a diet that addresses inflammation.
  3. Include probiotics and prebiotics in your diet.

Whatever course of action you choose, however, please do so with the guidance of your healthcare professional who can help you decide which option may work best for you. He or she can also help you choose an anti-inflammatory diet and the right pro-and prebiotics to take.

If you would like to know more about or need assistance with cortisol that interferes with your digestive system, the team at Dr. Lam Coaching can help. We offer a free** no-obligation phone consultation at +1 (626) 571-1234 where we will privately discuss your symptoms and various options. You can also send us a question through our Ask The Doctor system by clicking here.

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Dr. Lam’s Key Question

Research shows the connection between cortisol and the digestive system is a two-way street. High levels of cortisol inhibit the digestive system by shunting blood away from it and to the brain and muscles. Digestive issues coming from this lead to more stress and a greater need for cortisol.

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