Have you ever experienced a decrease in appetite or abdominal pain when you’re anxious or stressed? Or perhaps you’ve felt “butterflies in your stomach” when you feel nervous or excited? This is because the brain and gut are intricately connected through the gut-brain axis. The gut-brain axis includes various pathways that allow bidirectional communication between the central nervous system (the brain and spinal cord) and the gut. The vagus nerve connects the brain directly with the enteric nervous system (ENS), a dense set of nerve cells spread throughout the entire digestive tract from the esophagus all the way to the anus. There are more nerve endings in the ENS than the central nervous system, which is why researchers sometimes refer to the gut as “the second brain.” The ENS and the vagus nerve oversee many gastrointestinal (GI) functions including swallowing, secretion of fluids for digestion, detecting nutrients, production of neurotransmitters, and regulating immune response. Therefore, when we have stress or anxiety, we often experience GI symptoms such as abdominal pain, bloating, constipation or diarrhea.
New Research on the Two-Way Communication Line
On the other hand, recent research indicates that the opposite effect is also true- our gut health can impact our mental and emotional health. Our gut is home to trillions of diverse microorganisms that make up the gut microbiome. These microbes play a vital role in our digestion and metabolism. They break down food that our gut cannot do on its own and produce vitamins that the body absorbs and uses. Certain microbes are also involved in making neurotransmitters, chemical substances that send signals to other cells to function.
Serotonin and dopamine are two types of neurotransmitters produced in the gut. In fact, 90-95% of serotonin and 50% of dopamine in our body is stored in the gut. Serotonin helps regulate respiration, digestion, behavior, and neurological functions. Dopamine is released during reward-motivated behaviors such as eating certain foods, having sex, or doing any activities that you enjoy. Dopamine helps regulate our learning, attention, memory, and mood. Therefore, gut microbes not only support our digestion and metabolism, they can also impact our mental and emotional health.
However, infections or damage to our gut lining caused by irritable bowel diseases (Crohn’s disease and ulcerative colitis), diarrhea, or asthma can lead to an imbalance of “good” and “bad” microbes in our gut. This microbiol imbalance, called dysbiosis, can induce irritable bowel syndrome (IBS), anxiety, and depression.
How to Improve the Gut Brain Connection
Treatment for IBS, anxiety and depression is most effective from an integrative approach due to the bidirectional nature of the gut-brain axis. If you experience any of these concerns, consider working with a registered dietitian, behavioral health specialist, and GI doctor for support. Here are some ways you can improve your gut health and the gut-brain connection starting this week:
Fiber-rich foods can promote the growth of probiotics or the “good” bacteria in the gut. Probiotics feed on prebiotics, nutritious fibers found in many fruits and vegetables such as apples, bananas, plantains, pears, guava, asparagus, spinach, and root vegetables like jicama and sweet potatoes. Whole grains (including barley, buckwheat, farro, maize, millet, oats, and rye) and seeds (like flaxseeds, chia, and hemp) are also good sources of prebiotics. Focusing on fiber-rich foods can positively impact the composition of the gut microbiome.
Movement and exercise can also impact the composition of the gut microbiome. Moving our bodies, whether with low and high intensity, helps maintain the balance of the gut microbiome, enrich microbial-diversity, and rebalance dysbiosis. Incorporating pleasurable movement like taking walks, stretching, or an activity you enjoy can improve your gut and overall health.
There are many types of stress we experience in life: physical stress (injuries, surgeries, excessive exercise), physiological stress (including chronic undereating), psychological (jobs loss, housing loss), and psychosocial stress (trauma, death). Psychotherapy approaches that can help manage stress include cognitive behavioral therapy (CBT), dialectical behavioral therapy (DBT), relaxation therapy, and meditation. Working with a behavioral medicine specialist may help people learn to cope with stress and ease persistent GI distress.
Medication and Supplements
Work closely with a physician to take antibiotics only when necessary. While they can help treat certain infections, antibiotics disturbs the gut microbiome and can lead to GI distress if not properly addressed. Discuss with your physician and dietitian about supplemental probiotics if you’re experiencing persisting GI symptoms during or after taking antibiotics.