Can probiotics and prebiotics improve our mental well-being?
Your gut is the new frontier of neuroscience. Scientists now understand that bacteria in your microbiome affects your overall physiology, and they have recently uncovered a connection between that bacteria and your brain. This gut–brain axis has led to a new concept called psychobiotics — probiotics and prebiotics that can influence your mental well-being.
Consider this: You have 23,000 genes in your cells, but they are vastly outnumbered by the 2 million unique bacterial genes in your microbiome. “It has enormous implications for the sense of self,” former National Institute of Mental Health director Tom Insel, MD, told the New York Times. “We are, at least from the standpoint of DNA, more microbial than human.”
Our gut microbes are an essential part of our unconscious system that regulates our behavior, explains Timothy Dinan, MD, PhD, DSc, a professor of psychiatry at University College Cork in Ireland, in a 2015 paper in the Journal of Psychiatric Research. “The development of a complex gut microbiota in mammals has played an important role in enabling brain development, especially in terms of cognitive function and fundamental behavior patterns, such as facilitating social interaction and effectively dealing with environmental stressors.” And with this in mind, researchers hope psychobiotics may someday be used, either alone or in concert with other treatments, to alleviate anxiety, depression, and other mental-health issues — even, perhaps, autism and dementia.
The term “psychobiotics” was coined in a 2013 paper published in the journal Biological Psychiatry. At that point, it referred only to probiotics — live microbes that survive in the gut and have a metabolic effect.
“These bacteria are capable of producing and delivering neuroactive substances . . . which act on the brain–gut axis,” wrote lead author Dinan. “Evidence is emerging of benefits in alleviating symptoms of depression and in chronic fatigue syndrome. Such benefits may be related to the anti-inflammatory actions of certain psychobiotics and a capacity to reduce hypothalamic-pituitary-adrenal axis activity.”
More study of the emerging science has quickly followed and produced fresh insights on what actually constitutes a psychobiotic.