Stress and Moods' Relationship to the Gut: A Two-Way Street
Stress is a part of being human. We all experience some levels of physical, mental, and emotional stress in our day to day lives. On certain levels, stress can be healthy, prompting us to avoid danger, meet deadlines, or manage and navigate activating situations. However, outside of the normal stressors we encounter everyday, chronic stress, stress that lasts weeks, months, or even years, can take a serious physical and mental toll on the body and mind.
There is an increasing amount of research demonstrating the bidirectional relationship between the brain and the gut, referred to as the “brain-gut connection.” Scientists believe there is a “second-brain” in your gut called the enteric nervous system (ENS) consisting of millions of nerves and neurons lining every inch of the digestive system, from the upper esophagus to the rectum. The ENS allows for the communication between the brain and gastrointestinal system, leading to the interconnection of one’s nutrition and dietary habits, mood, and stress levels, ultimately causing these facets of someone’s life and body to have significant influence on one another.
Beginning with stress, there are a multitude of ways in which this feeling and physiological response alter the functioning of the digestive system. It can not only cause mindless eating and the overconsumption of non-nutritious foods, but can chemically and physically alter the bacteria in our guts. For example, excessive consumption of ultra-processed foods, animal protein, saturated fat, and artificial sugar can alter the bacteria and microbiome in the gut, causing lower bacteria diversity, inflammation, and an increased risk of developing digestive disorders such as irritable bowel syndrome (IBS) and symptoms of gastrointestinal distress such as bloating, nausea, constipation, diarrhea, indigestion and gas.
With the known connection between the brain and the gastrointestinal system, malfunctioning and an imbalance of bacteria diversity within the gut can in turn cause more psychological and mental stress, and even contribute to anxiety and depression. In fact, 90% of serotonin receptors, areas in which the mood modulating hormone serotonin attach to, are located in the gut. Studies demonstrate that individuals with IBS and other gastrointestinal disorders, such as colitis and Crohn’s disease, are more likely to present with neurological and psychiatric symptoms such as depression and anxiety. The activity of serotonin, as well as other neurotransmitters such as dopamine, in both the brain and the gut impact blood flow, nutrient absorption, and the microbiome, as mentioned previously. Given this, the food we consume and the bacteria in our intestinal tract can directly impact emotions, mood regulation, and stress, and vice versa.
So how can we live, and what can be implemented in our daily routine to promote gut health, reduce and manage stress levels, and take care of our overall mental, emotional, and physical health? Beginning with diet, plant proteins, unsaturated fats, and fiber support healthy bacteria in the gut and have anti-inflammatory effects. Whole foods including fresh fruits and vegetables, whole grains, legumes, seafood, lean poultry, and probiotic-rich foods such as kefir, plain yogurt, kimchi, and sauerkraut, all help populate your gut’s microbiome with beneficial bacteria. Reducing red meat consumption and highly processed foods, and limiting foods high in additives and preservatives which can disrupt healthy bacteria in the gut, can help protect against digestive disturbances and also have a positive impact on mood and stress regulation.
In order to maximize the positive effects of these dietary recommendations, the inclusion of exercise, stress management practices, and a healthy sleep cycle can bolster the effects of and add to the benefits of optimal nutrition. Studies show that exercise enhances the number of beneficial bacteria in the gastrointestinal system, ultimately producing positive health effects and disease prevention. Incorporating physical activity, whether it be walking, running, swimming, dancing, stretching, yoga, or strength training, into your everyday routine, as crucial as it is to overall health and wellbeing, can be a challenge. However little things everyday to keep the body moving counts, such as taking the stairs instead of the elevator, taking frequent stretching and walking breaks in between long periods of sitting, and using daily household tasks and chores as a means of movement. Finding exercise and joyful moments that you enjoy boosts energy and improves mental health, as well as supporting your digestive system.
Implementing practices to support mental and emotional health are equally as important as the physical-health promoting activities listed above. Journaling, meditation, mindfulness, and various relaxation techniques such as breath focus, deep breathing, progressive muscle relaxation, and guided imagery are simple means of reducing the impact of a negative stress response and the build-up of chronic stress. In fact, there have been specific studies conducted that demonstrate the improvement of symptoms, quality of life, and depression in IBS patients who participated in a five week course that included progressive muscle relaxation and diaphragmatic breathing, among other educational and psychological components.
While certain relaxation and stress management techniques have been demonstrated in studies to reduce stress and gastrointestinal stress, these methods, along with diet and movement, alone will not cure chronic stress, anxiety, depression, or digestive disorders and diseases. It is pertinent to seek appropriate medical and therapeutic treatment from licensed professionals and discuss what is best for your individual body and life circumstances. Further, exercise, proper nutrition, and adequate access to food can be difficult to attain with barriers such as lack of transportation, low-income, time, and geography. Within San Diego County, there are ample resources to assist with food insecurity and healthy eating . 2-1-1 San Diego is a free, 24 hour phone service and online database that can aid in finding social service resources, including food resources and information about the nutrition assistance program CalFresh, food banks and food distribution sites, the Summer Lunch Program, and Women, Infants, and Children (WIC) services that aim to offer nutritional information and education, counseling, and food assistance to women and children.