A study, published in The Journal of Neuroscience in May and funded by the National Health and Medical Research Council of Australia, could have revealed the science behind what is commonly referred to as our “gut feelings.”
Using a combination of various high precision neuronal imaging techniques on mice, researchers in Australia have been able to observe the functioning of the enteric nervous system (ENS) — a large network of neurons in the gastrointestinal system. Not only is the ENS the largest collection of neurons outside the brain, it is capable of operating entirely independently from the rest of the nervous system. This is why it is often referred to as the second brain. Researchers have been successfully able to document the rhythmic firing of neurons and subsequent contractions in the surrounding smooth muscle for the first time.
Traditionally, the ENS has been disregarded as something that only manages the gastrointestinal system (GIS) and nothing else. However, not only are the GIS and brain directly connected by the vagus nerve, a growing body of research suggests that it has a role beyond the management of our bowel movements and influences areas of health previously thought of as unrelated to the gut. A 2010 study, for example, found that serotonin released by the gut could cause osteoporosis.
In August 2017, researchers from from the Department of Psychiatry and Psychotherapy at the University of Regensburg, Germany conducted extensive research on the microbiome in the gut and its relationship with the brain. In the conclusion of their paper I am I and My Bacterial Circumstances, the authors wrote, “The evidence presented above suggests that the link between the microbiome-gut-brain axis, the neuroendocrine-immune system—including energy homeostasis mechanisms—and the neurodevelopment is strong.”
The documentation of the ENS’s rhythmic firing is an invaluable addition to the research helping us better understand the workings of our “second brain”. It is also safe to say at this point, that the ‘gut feeling’ we sometimes feel is a result of highly complex neurological activity that we have only begun to understand.