The further our knowledge about the human body advances, the more we learn how deeply interconnected many of our anatomical systems are. Neuroscientists first identified the gut-brain connection, a clear neurological pathway that connects our brain and digestive systems, in 2010.
Since then, researchers have explored how our digestive health affects our mental health, challenging the pre-existing notion that emotional conditions lead to digestive disorders. Like any communication channel, information travels both ways. Taking proactive steps to promote your gut-brain health can have cascading effects on your mental, emotional and physical wellbeing.
The Anatomy of the Gut-Brain Connection
The "gut" component of the connection concerns our entire gastrointestinal (GI) tract, including the esophagus, stomach, intestines, and rectum. It's where we break down food, absorb nutrients, and generate many of the chemicals necessary for other body processes. The entire GI system features the enteric nervous system (ENS). It's a thin layer of nerve cells that runs through the entire tract, sending signals that trigger GI responses to stimuli and changes in homeostasis. The ENS is capable of so many high-level neurological functions that it's often referred to as the "second brain."
The "brain" component of the connection entails our brain, spinal cord, and the central nervous system (CNS), the network of cells that controls every aspect of the bodily processes, from breathing to pulling our hand away from a hot stove.
The vagus nerve, one of the longest nerves in the body, connects the two, carrying signals back and forth. For example, the CNS sends messages to begin the production of digestive juices when we're about to eat. The ENS directs the manufacture of neurotransmitters and amino acids essential for neuron function. This constant communication means changes in one inevitably affect the other.
Beyond the trillions of cells that make up our bodies, we also contain trillions of microorganisms that exist symbiotically to help us fulfill many core biological functions. Collectively, these microbes form the microbiota, which is sometimes called our gut flora. Our GI tract relies on our microbiota to aid digestion, fuel enzyme synthesis, and manufacture neurotransmitters.
We begin acquiring our gut microbes in utero as they're passed on from our mothers. The microbe's ongoing development is unique to each of us, which contributes to the idiosyncrasies of each person's GI baseline. Over time, illness, antibiotics, and diet influence the breadth and vitality of the microbiota.
The microbes are necessary for the chemical relations needed to manufacture neurotransmitters, which our nervous system uses to facilitate its messaging system. More and more studies show that modulating the microbe impacts our mood and mental wellbeing.
Hormones and the Immune System
Beyond the direct communication across the gut-brain connection, our gut is essential for overall wellbeing. Gut health, digestion, and our microbe's balance influence hormone production, which impacts our mental acuity, brain health, and the aging process.
Gut health is also vital to normal and effective immune responses due to the balance of microorganisms through the gut. Imbalance and illness can lead to ineffective and counterproductive inflammatory responses.
How Do the Gut-Brain Connection and Mental Health Intersect?
If you've given a presentation at work and had butterflies in your stomach or felt your stomach "drop" when you sensed a dangerous situation, your brain has sent messages to the gut to slow down digestive processes, shifting the body's focus where attention is needed.
The ENS affects mental health in the same way. If your gut bacteria is out of balance or you're experiencing chronic constipation, your ENS will transmit signals to your brain that may alter your mood or focus. The emerging science on the connection is providing better insights into the best ways to manage mental health by treating the gut.
GI disorders are often challenging to diagnose. Individuals often undergo months of diagnostic procedures, laboratory testing, and FODMAPs to eliminate potential problem foods. Trial and error are frequently needed to identify and manage GI problems. Neuroscientists now are exploring the link between treating the mind to treat the gut and treating the gut to treat the mind.
The diverse microbe within our digestive tract is vital for the production of neurotransmitters. These chemicals bind to neurons, helping to facilitate messages. If our system is imbalanced, the resulting loss of neurotransmitters can elevate stress, anxiety, and depression. The gut's role in mental health cannot be overstated. Researchers believe up to 90% of our serotonin, the transmitter tied to "happy" signals, originates in the gut.
Promoting Gut-Brain Health
Individuals experiencing mental health challenges and those dealing with digestive disorders should take a holistic approach and investigate how their second brain may be impacting their emotions.
Humans evolved to digest whole foods such as lean proteins, vegetables, and fruits. A healthy diet makes digestion easier, lowering the stress the body expends to absorb nutrients. Minimizing your consumption or avoiding processed foods and ones high in fat and sugar reduces inflammation, improves circulation, and promotes a healthy microbiota
You should follow a diet that features:
- Protein from eggs, lean beef, poultry, fish, nuts, milk, broccoli, and oats. The nitrogen contained in protein suppresses the production of harmful gut bacteria while aiding the production of serotonin, which is vital for balancing one's mood.
- Fiber from beans, oats, nuts, fruits, and green vegetables. Fiber's antioxidant effect helps gut microbes flourish. It also has proven memory and mood-boosting effects.
- Vitamin D from egg yolks, tuna, salmon, orange juice, and fortified milk because it helps the body regulate your gut biome and eases inflammation.
- Omega-3s from walnuts, flax seeds, salmon, sardines, and mackerel. These acids increase memory and cognitive function.
The digestive system relies on chemical reactions fueled by acids and peristalsis to break down food for its nutrients. Creating optimal conditions for effective digestion includes staying hydrated. Beyond filtering toxins, water helps maintain chemical balance and cell health. Proper hydration is also vital to preventing constipation, which can significantly alter the biome.
Beyond the obvious cardiovascular benefits of following a consistent exercise routine, strengthening your heart improves circulation. Your ENS controls blood flow to your digestive tract. A well-functioning circulatory system will oxygenate digestive tissue, remove waste, and improve digestion. Keeping food moving through the tract is vital to maintaining the integrity of your gut's biome. Exercise helps keep your GI tract and bowels active.
The mood-altering effects that occur when the ENS signals the brain may be part of the feedback loop of stress. Controlling stress can help maintain your gut biome because unmanaged stress initiates inflammatory responses that dampen digestive activity and alter intestinal flora. Possible stress management techniques include:
- Cognitive Behavioral Therapy (CBT), clinical trials have linked CBT to a reduction in IBS symptoms and improved quality of life
- Progressive Muscle Relaxation (PMR) entails training yourself to detect muscle sensations that signal tightness and using exercises to release the tension, there is a link between prolonged muscle contraction and GI distress that may depress mood and elevate anxiety
When we eat at irregular times or go prolonged periods without food, we're prone to eating too quickly. This can lead to excessive eating because the signals from the gut to the brain do not communicate that the body is satiated fast enough.
Thinking about food, slowing down our dining, and applying mindfulness techniques to the meal helps improve digestion and portion control. This prevents us from overworking our digestive tract.
Probiotics are often the first recommendation for people struggling with irregular bowel movements or gastric distress because they help revitalize our microbiota. Probiotics' impact on the microbe also helps with mood. Researchers found greater activity in the region of the brain responsible for processing emotions in a recent study among participants who consumed yogurt with probiotics.
Foster the Gut-Brain Connection
You must monitor your health and wellbeing and examine the ways your mind and gut interact. If you've noticed changes in your mood, consider your diet and any change in gastric symptoms. If you've developed new constipation or diarrhea, conduct a self-assessment about your ongoing stressors and coping strategies.
The brain and gut are linked on a cellular and chemical level. What happens to one inevitably affects the other. Keeping an eye out for changes and taking proactive steps to strengthen your body, preserve your digestive health, and nurture your emotions can ensure the connection runs smoothly.