A second brain… in your gut?

By Casey Frye, CCNN Writer

You can find probiotics in food products like yogurt and soft cheese, or you can buy them in the form of a pill.

Scientists have always known there’s a connection between our stomachs and our brains. For example, anxiety can cause us to feel very nauseous and depression can make us feel starved or ruin our appetite. Although it’s been generally assumed that the brain affects the gut, recent research reveals the connection actually works both ways.

You see, there are trillions of healthy bacteria that live in our stomach and intestines, called probiotics. James Greenblatt, a psychiatrist who works in the Boston area, explains that they are collectively more like a brain than we think. “The gut is really your second brain,” he said. “There are more neurons in the [stomach and intestines] than anywhere else except the brain.” For that reason, the gut can have many brain-like influences!

According to a study from McMaster University, probiotics can affect our mood. When the researchers got rid of all the bacteria in mice they were studying, the tiny mammals were more likely to be anxious and depressed! Jane Foster, the leader of the research said, “Everybody knew that stress and anxiety could lead to gastrointestinal symptoms, but we… showed that the gut could communicate with the brain. It was the first demonstration that the gut itself could influence brain development.”

In a second study, the McMaster researchers used a timid group of mice and a brave group mice. When the scientists swapped the bacteria between the two groups of mice, they completely changed personalities! That is, the once brave mice were now timid creatures, and the scared ones became adventurous.

The psychiatrist, Greenblatt, has observed similar personality changes in humans. He once had a patient named Mary with obsessive compulsive disorder (OCD) and attention deficit hyperactive disorder (ADHD). Basically, she felt high levels of anxiety and had difficulty focusing sometimes. Mary’s parents struggled for years trying to find the right doctor and medication to treat her disorders, but no amount of prescriptions helped. That is, until they took her to Greenblatt. When he prescribed probiotics, her disorders soon seemed to disappear completely! Greenblatt is positive that prescribing bacteria is key to a healthy brain.

“There are beginning to be suggestions that this type of probiotic treatment is worth pursuing,” said John Bienenstock, another researcher. “Whether we can use this to improve people’s lives, well, the door is just beginning to open on this.” In other words, the results look promising, but we shouldn’t jump to any conclusions yet!

Featured image courtesy of University of Michigan Health System. Image of pills courtesy of Ashley Steel on Flickr.