Have you ever experienced butterflies in the stomach before an important meeting? Does attempting to “cure” the blues with Ben and Jerry’s sound familiar? If so, then you are already acquainted with the existence of a connection between our moods and our gut. Indeed, the brain and the digestive system are linked by complex pathways where information flows back and forth on a continual basis: certain feelings and thoughts can stimulate an exaggerated gut response, while sensitized nerves in the gut can trigger changes in the brain. The Nervous System and the “Second Brain” The nervous system is a complex
Stress can be lifesaving but when it becomes chronic, it has all sorts of negative impacts both on our physical and mental health. During this period and even now as we are trying to get back to a more normal life, many factors such as social Isolation, financial losses, concerns for loved ones and fear of contracting the virus are all adding up and taking their toll on our stress load. This emotional stress is affecting our overall health.
The gut-brain axis
Our whole digestive system – including our gut – is a lot more in sync with our brain than we may realize. Have you ever experienced how the simple thought of lemon juice increase your saliva production? Or the anticipation of giving a big presentation or another stressful event can lead to digestive discomfort? That is because our brain and our gastrointestinal system are in constant communication and this tight relationship implies that emotions and situations also have an impact our digestive process.
When we experience stress, we release stress hormones such as adrenaline and cortisol which enable the fight-or-flight response. During that process, digestion slows or even stops so that the body can divert all its internal energy to facing a perceived threat. The decreased blood and oxygen flow to the digestive organs can cause cramping and an imbalance in gut bacteria.[i] That is why chronic stress often manifests itself as abdominal discomfort and other symptoms of functional gastrointestinal disorders. Additionally, when foods get stalled in the digestive process, they undergo more fermentation and putrefaction, producing an increased number of by-products and toxins. The already compromised digestive system under stress must now also detoxify additional stress hormones and extra by-products created by the slowed-down digestive process.
Stress depletes essential nutrients
Another mechanism through which stress causes deleterious effects on our digestion and detoxification process is through the depletion of certain essential nutrients. The reduced stomach acid production, the disrupted microbiome interferes with the absorption of several vitamins including B vitamins and minerals such as magnesium which are crucial to our detoxification processes such as methylation.
Methylation consists of the transfer of a methyl group (one carbon atom & three hydrogen atoms) onto amino acids, enzymes, and DNA. The addition of a methyl group onto these molecules facilitates biochemical reactions vital to critical functions in our body such as: detoxification (especially in the liver), the proper functioning of the Hypothalamic-Pituitary-Adrenal (HPA) axis and critical for the synthesis of all neurotransmitters, fighting infections, turning on and off genes, repairing DNA, etc. When the methyl groups are used up by the stress response, their shortage will affect the detoxification process as well ass other organs like the pancreas, the brain, the thyroid, and the adrenals.
Moreover, the methylation cycle depends on important co-factors to function including the B vitamins i.e folate, B12 and B6. For optimal performance, these B vitamins must be in their activated form, namely methylcobalamin, folinic acid, 5-MTHF and pyridoxyl-5-phosphate. When we are undergoing chronic stress, our body calls upon its store of B vitamins, vitamin C and magnesium to cope with this added pressure. Since vitamins B and vitamin C are water soluble and eliminated from our body very quickly, we depend on a consistent supply through diet and/or supplements to meet our needs.
Chronically elevated cortisol produced during the stress response also impacts the integrity of our gut walls by depleting the body’s L-glutamine store.[ii] A significant amount of the amino acid L-glutamine is used as fuel by our enterocytes, the cells that build our gut lining.[iii] Low level of serum glutamine concentration correlated with intestinal barrier disruption (also called ‘leaky gut’).[iv] Both of these conditions are known to be important contributors to stress and mood dysregulation.[v]
Glutamine is also used in the production of GABA, our most abundant calming amino acid. Consequently, a glutamine deficiency is detrimental to a healthy stress response.
There are several things we can do to reduce stress and improve our digestion. Practicing stress-management techniques, exercising regularly, getting sufficient sleep and socializing are all important to minimize our levels of stress. In addition, we can support our digestive health by drinking fewer alcoholic beverages, reducing our sugar intake, and eliminating gluten. Increasing health-promoting foods such as those rich in probiotics, fibers and enzymes through a predominantly plant-based diet goes a long way. Consider supplementing with appropriate supplements to manage stress, support the detoxification pathways and a healthy gut, as needed.
[ii] Brillon, D. J., B. Zheng, R. G. Campbell, and D. E. Matthews. Effect of cortisol on energy expenditure and amino acid metabolism in humans. Am. J. PhysioZ. 268 (Endocrinol. Metab. 31): E501-E513, 1995. https://journals.physiology.org/doi/pdf/10.1152/ajpendo.1995.268.3.e501
[iii] Rao R, Samak G. Role of Glutamine in Protection of Intestinal Epithelial Tight Junctions. J Epithel Biol Pharmacol. 2012;5(Suppl 1-M7):47-54. doi:10.2174/1875044301205010047
[iv] Rao R, Samak G. Role of Glutamine in Protection of Intestinal Epithelial Tight Junctions. J Epithel Biol Pharmacol. 2012;5(Suppl 1-M7):47-54. doi:10.2174/1875044301205010047
[v] Clapp M, Aurora N, Herrera L, Bhatia M, Wilen E, Wakefield S. Gut microbiota’s effect on mental health: The gut-brain axis. Clin Pract. 2017;7(4):987. Published 2017 Sep 15. doi:10.4081/cp.2017.987