For the study, published in the journal Gastroenterology, researchers divided 36 healthy women between the ages of 18 and 55 into three groups. One group ate yogurt containing a mix of several probiotics twice a day for four weeks, another consumed a dairy product that looked and tasted like yogurt but contained no probiotics, and the third group had no yogurt products. At the end of the four weeks, the women’s brains were scanned in a state of rest and in response to an emotion-recognition test where they viewed a series of photos of people with angry or frightened faces and matched them to other faces showing the same emotions. Emeran Mayer, MD, a gastroenterologist at the UCLA Medical Center and senior author of the study, says this test is effective for measuring brain function because recognizing the emotions of others is necessary for survival. More from Prevention: How Probiotics and Prebiotics Help Your Health When the researchers compared the scans with ones taken before the trial, they found that those who had eaten the yogurt with probiotics had a decrease in activity in the area of the brain that controls emotion, cognition, and sensory feelings in response to the emotion-recognition test. Those who had no probiotics had an increase in activity, meaning they reacted more to the negative images. It’s understood that the brain can affect the gut (that’s why stress can cause stomach problems), but “this proves the concept that if you manipulate the gut flora you will have an effect at the brain level,” says Dr. Mayer. Previous studies found that probiotics relieve anxiety in mice, and Dr. Mayer says future studies are planned to investigate if the bacteria could have similar effects on humans’ emotions. And while it’s too soon to prove some of yogurt’s health benefits, if you like the taste, keep eating it, he says. Other fermented products like wine, some naturally brewed beers, and cheese, are also sources of probiotics. More from Prevention: Can Probiotics Help You Lose Weight?
