Lately, probiotics have become pretty well-known in media and health reports as crucial bacteria and yeasts that thrive in, and benefit, your digestive system. Yes, there is such a thing as good bacteria. Unlike the bad bacteria that cause flu and sickness, probiotics are the good guys fighting to keep you healthy.

A new study out of the Leiden Institute of Brain and Cognition at Leiden University in the Netherlands suggests that probiotics may actually aid in improving mood. They might be a good way to fight anxiety or depression, or simply make you feel better after a bad day.

Another recent study found that people who took probiotics experienced lower levels of anxiety and depression, and had lower levels of cortisol otherwise known as the stress hormone — in their saliva when they woke up in the morning.

“Even if preliminary, these results provide the first evidence that the intake of probiotics may help reduce negative thoughts associated with sad mood,” said Lorenza S. Colzato, an author of the study, according to Time “As such, our findings shed an interesting new light on the potential of probiotics to serve as adjuvant or preventive therapy for depression. Go out and get some Greek yoghurt or look for dairy yoghurts that have the label “with probiotic cultures”, there is also cultured buttermilk for those with acquired taste buds.