Our country’s celebratory bicentennial year and my 10th year—1976—returns me to a dizzying amount of transition and change in our family: my mother’s remarriage, a move into the city in the middle of third grade, my mother’s unexpected hospitalization for a sudden, but non-life-threatening illness, and the unimaginable loss of 3 grandparents. My anxiety surely predated these events, but it is not a surprise that my level of distress and discomfort was ratcheted up in volume and intensity. I was a mini train wreck, unable to understand cognitively what my body—particularly my gut—was communicating. Various and dreadful GI tests revealed that my gut was functioning “normally,” despite symptoms that were so painful and disruptive, my anxiety focused exclusively on my gut’s seeming inability to do its job quietly and without rebellion.
More than 40 years ago, there was very little information about the importance of the gut-brain connection, and my very unhelpful diagnosis of gastroenteritis (today I would most likely be diagnosed with IBS) led me no closer to symptom relief. I have no specific memories of when or under what circumstances my symptoms and anxiety quieted, but by 5th grade—and during another family move mid-year—I was well again.
This is a long-winded introduction to a subject that for personal and professional reasons has captivated my attention and desire to understand why the gut-brain axis plays such a fundamental role in our physical and mental health. The gut and its microbiome affect virtually every aspect of our body’s functioning: immunity, body weight, metabolism, and mood, among others.
First, definitions of some terms that have become buzz words in the health and medical community:
The gut microbiome comprises trillions of bacterial, fungi, and other microbes. Our gut microbiome helps control digestion, metabolism, the immune system, and other key aspects of our health.
The gut-brain axis refers to the communication system between the gut and the brain.
The vagus nerve is one of the largest nerves connecting the gut and brain, sending signals in both directions.
The gut and brain are also connected through chemicals called neurotransmitters, which in the brain control emotions and feelings (e.g., serotonin leads to feelings of happiness and helps control our circadian rhythms). Neurotransmitters are also produced in the gut.
Probiotics (“helpful bacteria”) are the good guys of our microbiome, as they crowd out harmful bacteria and help us maintain overall health. They are live bacteria and yeasts that benefit the digestive system.
Prebiotics are a type of fiber. They are the indigestible plant fibers that feed the probiotics in the gut.
Some really astounding facts about the gut:
90% of our serotonin is produced in the gut.
80% of our immune system resides in the gut.
The average adult carries 5 pounds (!) of good bacteria in the gut alone.
Every organ in the body is connected with the gut.
When the gut is spread out, it is the size of a basketball court.
We have 100 billion neurons in the brain, and 500 million in the gut.
The gut is home to the enteric nervous system (ENS) which has more nerve cells than the spinal cord.
The key roles of the gut include digestion, absorption of nutrients, providing the main immune barrier to the outside world, detoxification, and the production of vitamins and neurotransmitters. When we have “butterflies in our stomach” or a “gut feeling” about something, these are powerful signals and guides to our emotional and physical health. It is no wonder the gut is referred to as the second brain.
Because our gut is responsible for creating most of our feel-good neurotransmitters (serotonin, GABA, dopamine), a healthy gut is essential for optimal physical and emotional health. Diets that consist of healthy, whole foods are linked with a reduced risk for depression. In order for the trillions of good gut bacteria to flourish, we need to be feeding our microbiome the right kinds of food. Diet appears to be the most important factor affecting the gut, and we can alter our microbiome within days just by changing the foods we eat.
Signs that our digestive system is out of balance are not always limited to more obvious digestive complaints. Changes in mood, a weakened immune system, skin irritations and conditions, and fatigue may all be signals that our gut is lacking good bacteria. More obvious digestive issues include constipation, diarrhea, bloating, and bad breath.
To begin healing the gut, first remove any foods that may be triggers. These may include (but surely are not limited to) highly processed foods, alcohol, dairy, wheat, gluten, peanuts, soy, corn, citrus, and eggs. Bad bacteria feast on refined sugar, so limiting your sugar intake is crucial to overall health.
Reinoculate the gut with healthy bacteria in the form of probiotics (supplement) and fermented foods (sauerkraut, kimchi, miso, kombucha, kefir, and yogurt).
Rebalance the gut through yoga, deep breathing, meditation, and stress reduction. Sometimes called the rest and digest system, the parasympathetic nervous system conserves energy as it slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles in the gastrointestinal tract. This state is reached when our stress hormone levels are low and we are feeling calm and relaxed. The opposite of the rest and digest system is the anxiety-triggered fight or flight response.
Eat plenty of healthy, polyunsaturated fats that are high in omega 3s and 6s such as olive oil, avocados, eggs, fatty fish, and nuts. Also load your plate with prebiotic-rich foods such as artichokes, onions, garlic, leeks, asparagus, honey, and others.
Published studies at Johns Hopkins Medical Center reveal that for decades, researchers and doctors thought that anxiety and depression contributed to GI distress. “But our studies show that it may be the other way around. Researchers are finding evidence that irritation in the GI system may send signals to the central nervous system that trigger mood changes. These new findings may explain why a higher-than-normal percentage of people with IBS and functional bowel problems develop depression and anxiety.”
Next time your gut speaks, listen carefully and with openness. We have so much to learn from our bodies if we could only slow our pace and listen.