You've probably heard the expression gut feeling or gut reaction. Well, it turns out our bellies are more than simply places to digest the food we eat.
In the early 1900s, Byron Robinson, physician and researcher, wrote The Abdominal and Pelvic Brain, in which he explains that humans actually have two brains: one in our stomachs and the other in our heads. The abdominal brain is independent from the cerebral brain and receives and generates information through a complex web of some 100 million neurons embedded in the walls of the digestive tract. An emerging field of neurogastroenterology is beginning to uncover just how much the two brains communicate and how this secondary brain might influence our physical, mental and emotional health.
The gut could play a vital role in our emotional and physical wellbeing.
"Some of the signals that the gut sends to the brain are important to wellbeing," says Michael Gershon, M.D., author of The Second Brain and chairman of the department of anatomy and cell biology at New York-Presbyterian Hospital/Columbia University Medical Center. The second brain sends messages to the cranial brain and could be instrumental in modifying our emotions. He cites butterflies in the stomach as one example where the brain communicates anxiety to the gut and it in turn tells the brain it's not happy.
A key ingredient in the gut-brain connection, serotonin acts as a neurotransmitter, regulating mood, appetite, memory, sexual behavior and sleep. "Serotonin plays a critical role in the creation of happiness," Gershon explains. Often referred to as a feel good hormone, 95 percent of all serotonin produced in the body is in the gut, whereas only 2 to 3 percent is found in the brain.
Indeed, conditions such as depression and anxiety reveal symptoms in the brain and the belly, while intestinal disorders such as irritable bowel syndrome or IBS can arise in part due to an oversupply of serotonin. Antidepressants like selective serotonin reuptake inhibitors or SSRIs that treat depression are also effective in IBS patients leading some researchers to view the brain and gut as one system.
Numerous studies, for example, have shown that the gut has a significant impact on the brain.
Premysl Bercik, M.D., associate professor of gastroenterology at McMaster University, and his colleagues gave BALB/c mice that are characteristically timid and slow moving a cocktail of antibiotics to alter the composition of gut bacteria. "Their behavior totally changed," Bercik says. "They became more active and exhibited fewer signs of anxiety."
Emeran Mayer, M.D., is a professor in the departments of medicine, physiology and psychiatry and bio-behavioral sciences at UCLA and director of a renowned integrated-research program that studies the role of brain-belly interactions in digestive disorders. He notes the critical role of the gut in affecting our minds. "If something goes wrong in the gut, that change is reflected in the brain."
In his clinical practice, Mayer helps patients understand mind-body interactions based on research findings and recommends relaxation and mindfulness techniques in addition to simple lifestyle changes. "Many of my patients have had troubled early childhoods and it's very satisfying to sometimes see marked improvement in patients' wellbeing after just one visit." Yet Mayer adds that the notion of the gut's importance isn't new, and, is in fact shared by many ancient healing traditions.
Science is finally catching up to a concept that age-old wisdom has known for thousands of years.
"As above, so below," an ancient Taoist saying describes the link between our brains and our bellies. In Japanese culture, the term hara, which means belly, is the physical and spiritual centre of a person's being, yet it also refers to one's state of mind and character. In Chinese culture, tan tien defines the belly as the seat of feeling and awareness, and the source of chi or energy. The sacred dances, martial arts, healing arts and body prayers of many ancient cultures in North America, Europe, Africa and India, honor the belly and acknowledge its wisdom and power as our natural center.
It is, writes Byron Robinson in his 19th century groundbreaking book, "the center of life itself."
Philip Shepherd, author of New Self, New World: Recovering Our Senses in the 21st Century, agrees with Robinson yet takes it a step further to say the "pelvic brain is the center of one's being."
According to Shepherd, we have been instructed since infancy to live in our heads, and that is why there is an overwhelming increase in psycho-emotional diagnoses. "Our culture doesn't recognize that hub in the belly, and insists that our thinking happens exclusively in the head." He explains that this way of thinking is detrimental to our wellbeing as it signals a loss in our capacity to truly understand the world and ourselves.
It's no easy task to let go of the mind's chatter and surrender to the experience of not only being in our bodies, but of being -- period. Modern distractions from smart phones, email, tablets, social network sites, and the web, engage our heads often making it impossible for us to feel centered. In his mind-body integration workshops Shepherd teaches his students that daily exercise, relaxation and mindfulness exercises can help us reconnect our heads to our "pelvic" intelligence. "Approaching our bodies as an integrated whole whereby the head and belly unite in an intimate relationship of healing, nurturance and wholeness will have dramatic and positive consequences for our wellbeing."
Shifting our worried minds to the present moment by engaging in a 20-minute run, walking meditation or simply being present during a five-minute morning shower can allow us to come back to our bodies -- or more precisely, to our bellies -- with a clearer sense of our inner resources, and of what we need to lead joyful and healthy lives.