People who suffer from depression could benefit from getting dirty, according to new research published in the journal Neuroscience. A “friendly” bacteria (Mycobacterium vaccae) found in soil has the same uplifting effects as those produced by anti-depressant drugs, scientists at Bristol University and University College London found. The bacteria stimulated the immune system of mice and activated a group of neurons in the brain which produce the mood-enhancing chemical serotonin. Dr Chris Lowry, from Bristol University, said: “[These studies] also leave us wondering if we shouldn’t all spend more time playing in the dirt. This soil which carries the bacteria is found almost anywhere. We now need to find a way of getting it in our system.” The current project arose after human cancer patients being treated with M. vaccae unexpectedly reported feeling their quality of life had improved.