Over on the NIH Director's Blog today, there's an interesting post about research efforts aimed at determining how the colonies of bacteria in our gut could play a role in mental health. As described in the piece, past research has shown there are a number of ways microbes can influence our thoughts, behavior and mood:
First of all, and perhaps most obviously, gut bacteria are engaged in a wide range of biochemical activities, producing metabolites that are absorbed into the human bloodstream. But there are other connections. One species of bacterium, for example, sends messages that are carried via the vagus nerve, which links the intestinal lining to the brain. When this species is present, the mice demonstrate fewer depressive behaviors than when it’s absent. Another bacterium plays an enormous role in shaping the immune system, which goes awry in many neurological diseases. This species of bacterium interacts directly with the immune system’s regulatory T-cells to provide resistance against a mouse version of multiple sclerosis, a progressive disease in which the immune cells damage the central nervous system by stripping away the insulating covers of nerve cells.
As Stanford microbiologist and immunologist Justin Sonnenburg, PhD, commented in a past entry on Scope, "There’s no doubt about it. These microbes are influencing every aspect of our neurobiology. There’s a direct connection between the microbes inside our gut and the central nervous system. They’re influencing our behavior, our moods, even our decisions."
Previously: Could gut bacteria play a role in mental health?, Study shows probiotic foods may alter metabolism, but can they boost your health? and Study shows intestinal microbes may fall into three distinct categories