New Evidence Shows Probiotics Could Help Fight Depression

It’s no secret that eating yogurt can increase your calcium intake and help keep you regular. But new research has found it may even help boost your mood. (Photo: Getty Images) 

Scientists from the Netherlands’ Leiden Institute for Brain and Cognition have discovered that probiotics, the live microorganism commonly found in yogurt, can reduce feelings of depression.

In the small study, researchers asked 40 healthy participants to mix a powder containing either two grams of probiotics or a placebo with warm water or milk every day for four weeks. Participants also answered a questionnaire that measured their likelihood of experiencing depressive thoughts before the experiment began and after the four weeks was over. Researchers discovered that those who took the probiotic powder showed a significant reduction in negative thoughts, especially ones that were aggressive or ruminative.

Lead researcher Laura Steenbergen tells Yahoo Health her team is surprised by the findings and excited about what they could mean for the future of preventing depression. “Ruminative thoughts are most important in predicting the onset and development of depression,” she says. “This makes the effect of probiotics on cognitive reactivity to sad mood a promising finding.”

Related: The Number One Cause Of Depression — Everywhere 

Probiotics have long been proven to promote the population of “good” bacteria in the gut, keeping your digestive tract balanced and working right. While research on the role probiotics plays on mood is still relatively new, other studies have shown that there is steady communication between your gut and your brain.

One study published in the journal Nature found that the gut can impact higher brain functions like intuitive decision-making, and an Australian study published earlier this year also discovered that psychological distress can cause gastrointestinal disorders to develop and vice-versa.

More recent research has even found that the communication involves interactions with the brain and microorganisms in your intestines, says nutritionist Heather Mangieri, RD, a spokesperson for The Academy of Nutrition and Dietetics. Essentially, if your gut is working well, it may have a direct and positive influence on how you think.

While this particular study focused on a probiotic supplement, Mangieri says it’s a good idea to try to get your probiotics through foods like yogurt, kefir, aged cheeses, kimchi, pickles, tempeh, and sauerkraut in order to get nutritional benefits along with your probiotics.

Related: Think Your Friend Is Depressed? Here’s What To Say (And What Not To) 

It’s also important to consume probiotics regularly in order to reap the benefits, probiotic expert Mary Ellen Sanders, PhD, tells Yahoo Health. So, eating a yogurt once a week won’t have the same impact as if you eat one a day. However, if you don’t have constant access to those foods or don’t like them, she says a supplement is fine.

If you decide to try a probiotic supplement, Mangieri recommends checking the expiration date  and following the instructions for proper storage since probiotics are a live microorganism. And, while no studies have been done that show probiotics could be harmful to healthy people, she also notes that people suffering from a serious illness such as cancer should avoid them.

Steenbergen points out that study participants were given a particular mix of probiotics (specifically, Bifidobacterium bifidum W23, Bifidobacterium lactis W52, Lactobacillus acidophilus W37, Lactobacillus brevis W63, L. casei W56, Lactobacillus salivarius W24, and Lactococcus lactis (W19 and W58)) and isn’t sure whether one in particular affected mood or if another dosage, form, or mix would show similar benefits.

While more research is needed on the exact link between probiotics and mood, its overall health benefits are pretty clear. But how much probiotics should we strive to consume regularly? Unfortunately, experts say because the amount of live and active cultures in probiotics is hard to measure, there is no magic amount. However, Mangieri says, “the more, the better.”

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