The role your second brain is playing in your health and consciousness
From:
by Cécile Denjean
“The ego is not master in its own house” — Sigmund Freud
For so long, much of what we have considered ‘self’ in the 20th century (notions like our ego) has been traditionally thought to reside in the brain. In her 2013 documentary “The Gut: Our Second Brain”, French director Cecile Denjean shows how modern science is forcing us to reconsider these notions.
It turns out we have a second brain which shares striking similarities to the seven pounds of gray matter packed into our skulls. Our gut is home to 200 million neurons which line the digestive walls of our intestines. While your upper brain houses your central nervous system, your lower brain manages the enteric nervous system. Signals from your enteric nervous system are sent up to your brain, and while they do not manage to reach your consciousness, those signals end up effecting how your brain sees the world. Some scientists are now beginning to ask whether the gut is actually our subconscious.
“Your ability to think happily, your ability to think well, your ability to resist depression and anxiety can be very influenced by the messages that the gut sends the brain. So to that extent, it is a contributor to your unconscious.” -Michael Gershon, Columbia University
The neural network in your gut forms an information system about the size of a dog’s brain. By storing information in your ‘second brain’, your body is peripheralizing information like an external hard drive so your brain doesn’t need to expand in size to increase storage. Together, your two brains are connected by the vagus nerve and they communicate using the language of neurotransmission. One of the words in this language is Serotonin. Most of us are familiar with the role a lack of Serotonin plays in depression, but 95% of the body’s supply is actually produced in the gut, not the brain. When released by the gut, Serotonin acts on the brain and influences our emotions. Our dreams are particular sensitive to the Serotonin emission during our sleep, thus accounting for many of those wife’s tales about not eating certain foods before bed.
Bruno Bonazz at the University Hospital of Grenoble, has been studying the role stress and traumatic events play in causing diseases such as irritable bowel syndrome (IBS). In times of stress, it is the stomach which sends signals to the brain, a gut-reaction if you will. Bonazz has been using hypnosis to relieve the symptoms of IBS as hypnosis modulates areas of the brain involved in pain. An interesting sidenote to Bonazz’s work is that it has shown that hypnosis, which affects consciousness, is not just all in the mind. It has a neural, anatomical and functional component as well.
The University Hospital of Nantes has found that many diseases which effect our brain, like Parkinsons and autism, may actually originate in our gut and then spread gradually along the central nervous system. What have become accustomed to associating with these diseases is only their advanced final stages. To test their theory, gastroenterologists teamed up with neurologists to fight Parkinsons and began taking a less invasive form of biopsies from the gut. There they found the presence of same lesions which were affecting the brain. Being able to perform these routine biopsies of the gut, as opposed to brain, are not only much safer, but offer a huge help in providing early diagnosis as the digestive symptoms of Parkinsons (constipation or the impairment of the sense of smell) can occur 20 years before the onset of motor symptoms.
Studies are now being conducted into Alzheimers, autism and other psychiatric pathologies. This may lead to a day when psychiatric treatment incorporates a wholistic approach, simultaneously treating both brain and gut health.
There are one hundred thousand billion bacteria living in your digestive tube. This is a thousand times more bacteria than there are stars in our galaxy. We are in fact an ecosystem in which there is a partnership between ourselves and our bacteria. Bacteria converts our food into energy and, in exchange, we provide them room and board. Your immune system gets an education by what the bacteria tell it. By keeping your bacteria well-exposed to various types of bacteria, it keeps your immune system alert. Imagine if your immune system were a boxer, only ever sparring with other boxers. Then, one day, it had to fight a kickboxer followed by an MMA fighter. Dude would be toast.
“We are more bacteria than we are human. We have many more bacterial cells on our bodies in our bodies, than we have human cells. We have more bacterial DNA than we have human DNA. So, we are like passengers inside a bacterial bus if you will.” — Stephen M. Collins, McMaster University, Canada
Researchers have found that adjusting the microbiota in the gut of mice directly impacts the levels of risky behavior they participate in. This has lead them to the conclusion that when your bacterial health is good, the bacteria want to survive, to continue living. One of the ways bacteria may seek to achieve this outcome is by sending unconscious signals to your brain which regulates risky behavior.
The converse is also true. Certain conditions in your gut can both increase your risky behavior and decrease your empathy for other people. Mice who were overly docile had their personalities changed when the bacteria from the gut of aggressive mice was transplanted into theirs. This should come as no surprise to us as bacteria have been around this planet long before we have and their genetic repertoire which is much greater than our own.
From the time we are born, certain activities, like breastfeeding, promote positive impacts on our bacterial ecosystem through the introduction of positive bacteria. While others contribute to depression, an inability to cope with stress and eventually chronic disease.
For years, the benefits of yogurt, kefir and kombucha have been lauded for their ability to positively influence our gut health. But at the Center for Neurobiology of Stress in Los Angeles, Kristen Tillisch was dubious of the effects of probiotics on our brain states. She decided to study 60 healthy women with no known issue of gut health. She fed the group yogurts, some with no probiotics and others with probiotics. When the group who took the probiotics were exposed to stressful images, a network of brain regions was less active. This implied that people who took probiotics are less reactive to those images. Something in their brain is changing the way they are responding to potentially negative stimuli in their environment.
I loved this documentary. It is amazing to see how our digestive tract is a microcosm of what we experience in the macrocosm of our planet. As you see the sciences beginning to coalesce and discover the interconnectedness of things, as we see the over-specialized and compartmentalized world of medicine pan out and take an interdisciplinary approach to understanding the human body, it gives me hope that we may be able to put Humpty Dumpty back together again.