Some researchers believe that the microbiome may play a role in regulating how people think and feel.
By now, the idea that gut bacteria affects a person’s health is not revolutionary. Many people know that these microbes influence digestion, allergies, and metabolism. The trend has become almost commonplace: New books appear regularly detailing precisely which diet will lead to optimum bacterial health.
But these microbes’ reach may extend much further, into the human brains. A growing group of researchers around the world are investigating how the microbiome, as this bacterial ecosystem is known, regulates how people think and feel. Scientists have found evidence that this assemblage—about a thousand different species of bacteria, trillions of cells that together weigh between one and three pounds—could play a crucial role in autism, anxiety, depression, and other disorders.