Anyone who’s struggled with anxiety or depression knows how debilitating they can be. It’s estimated that about 19 Million Americans are dealing with clinical depression at any given time. And even though only about one-third of them will actually receive treatment, it’s also estimated that depression exacts an economic cost of over $30Billion each year.

And those medications often come with a good many side effects of their own.

Fortunately, new research shows there may be a simpler, more natural way to combat both depression and anxiety: A certain strain of probiotics.

An international team of researchers found that mice who drank a broth spiked with the organism Lactobacillus rhamnosus were less likely to be anxious or stressed than control mice who drank a bacteria-free broth. The mice who drank the probiotic broth also produced less of the stress hormone corticosterone in their brains in response to a stressful event compared with the control group of mice.

The researchers found there is a nerve – the vagus nerve – that connects the brain with other parts of the body, including the digestive tract. When that nerve was severed the probiotics didn’t have the calming effect on the mice.

It appears that Lactobacillus rhamnosus helped normalize the expression of important neurotransmitters in the brain that would naturally be turned up or turned down when animals become stressed or anxious. But other strains of probiotics, such as Lactobacillus salivarius and others found in commercial yogurts had no effect.  

So again, the strains of probiotics in your supplement matter.