Gardening 2016-03-24

So the bacterium had a similar effect on the mice as an antidepressant drug might. When we dig in soil we ingest – or absorb – the bacterium through our lungs or cuts in our skin. A placebo, by the way, is a substance with no physical effects that is used when testing a drug. So here one group of mice were injected with the bacterium and another group were injected with the placebo. And since the mice seemed happier when treated with soil bacteria, there's a good chance we would too.