Although anxiety is the most common mental health issue in the US, affecting 40 million adults every year, only 37 percent of those dealing with it seek treatment, according to the Anxiety and Depression Association of America. There are many reasons behind that, from the cost of treatment to stigma to the anxiety simply going undiagnosed, but it's a statistic that makes research like a recent scientific review all the more important.
In that review, published in General Psychiatry, researchers from the Shanghai Mental Health Center at the Shanghai Jiao Tong University School of Medicine looked at the results of 21 studies that had examined over 1500 participants to see what effect gut bacteria could have on anxiety symptoms. Seem surprising? It's actually not; as the authors pointed out, a growing amount of research has indicated that this bacteria may have a few roles to play in regards to brain and mental health. That includes facilitating communication between the nervous, immune, and endocrine systems, which together are known as the "gut-brain axis" — just to drive the point home that all of these areas are closely intertwined.
So how do you keep gut bacteria healthy? One way is through probiotics, microorganisms present in foods like yogurt, miso, and tempeh, and drinks like the popular kombucha. Another way is to overhaul your diet through eating plans like the low-FODMAP diet, which cuts out groups of carbs that are known to cause digestive distress like bloating, gas, and stomach pain. The researchers looked at both of these options to see if either could help address the symptoms of anxiety.
Their findings were encouraging. Of the 14 studies that used probiotics, 36 percent of participants reported improvements in their anxiety symptoms. In the six studies that used nonprobiotic methods, like dietary changes, the results were even more positive: 86 percent said the changes were effective. And taken altogether, more than half of the studies found that regulating gut bacteria — whether through probiotics or dietary changes — helped to improve anxiety.
The difference in effectiveness could be down to a few different factors. Changing your diet, the researchers explained, doesn't just change your food source, but your gut bacteria's as well. And just as eating more protein helps your muscles grow, eating more gut-friendly foods can help the bacteria already in your intestines flourish (instead of simply introducing more of that bacteria, which is what happens with probiotics). That cause-and-effect chain can ripple on up to your brain, improving your mental health as well.
Though the researchers looked at a wide range of studies, they noted that the review was essentially observational; that is, they can't prove that regulating gut bacteria was the exact variable that improved anxiety symptoms. More studies will need to be done before we get to that point. Still, even just the potential of a more accessible solution for a mental illness like anxiety — one that affects so many and often goes untreated — is a step in a positive direction.
If you want to learn more, be sure to review the physical symptoms of anxiety (which include increased heart rate, headaches, and a feeling of butterflies in your stomach), read about what it's like to live with anxiety, and learn tips for dealing with it. Always speak to a doctor before making dietary changes or if you think you may have anxiety.