In the past, clinical data from rodent experiments have demonstrated a link between the type of bacteria growing in a mouse’s gut and its ability to remain calm in stressful situations. A newer study finds similar linkage in humans.
You are what you eat, so the saying goes. In fact, the trillions of bacteria inhabiting your gut also eat what you eat, and turn meals into molecules that affect your brain — and some researchers believe those bacteria can have a serious impact on mood and mental health.
It’s referred to as the “gut-brain axis.” And it can be a healthy and positive relationship, or a serious health problem in the case of Crohn’s and other forms of inflammatory bowel disease, which affect one out of 150 Canadians.
A team of researchers at the University of Manitoba (Canada), headed by Dr. Charles Bernstein (a professor of gastroenterology) noticed that mood disorders in people with Crohn’s and other forms of inflammatory bowel disease often precede gut problems.
He thinks the trillions of bacteria in a person’s bowel affect both mood and gut function.
“Having bacteria in your bowel triggers an immune response, and if the trigger is an aberrant immune response, some of that immune response may also impact on brain function,” Bernstein said.
“By manipulating the bugs in the bowel, one may be able to improve the mood disorder.”
The idea of treating Crohn’s and its mood effects by manipulating gut bacteria is certainly intriguing.
Bacteria are tiny chemical factories. The molecules they produce could affect the brain in two ways. Some of the chemicals they make can travel in the bloodstream all the way to the brain. A few small protein molecules of bacterial origin have been traced in this way.
The other way your gut bacteria can affect mood is through the neurological links between the gut and the brain. Your intestines are suffused with large numbers of neurons that feed information to the autonomic nervous system. The signals that are feeding back from your gut to your brain via this pathway are not yet well understood. In earlier clinical research, the actions of certain bacteria on the neurons in the gut translated to increases in GABA (a neurotransmitter that chills things out in your brain). So there is evidence for this indirect link as well.