Can the probiotics in yogurt really help to relieve stress? Researchers at the University of Missouri think that may be case, although their suspicion is based on experiments with zebra fish, not people. A U of Missouri news release reports that the researchers tested how zebrafish behaved after doses of Lactobacillus plantarum, a common bacteria found in yogurt and probiotic supplements. In the first study, scientists added the bacteria to some tanks housing zebrafish, while other tanks of zebrafish received no probiotics. The researchers then introduced environmental stressors to both groups, such as draining small amounts of water from the tank and overcrowding. By analyzing the gene pathways of both groups of fish, the research team found that zebrafish that were given the supplements showed a reduction in the metabolic pathways associated with stress. Wait, there’s more. The researchers also measured the movements of fish in their tanks using sophisticated computer measuring and imaging tools. Previous studies of fish behavior have found that fish that are stressed tend to spend more time at the bottom of their tanks. Once the fish were administered probiotics, they tended to spend more time toward the top of the tanks — suggesting that they were less stressed or less anxious.