That's true- and on that note I wonder if it's the gut in general and it's all related in a cycle. (Given the compounding evidence your gut directly affects your brain.)

From http://www.hopkinsmedicine.org/health/healthy_aging/healthy_...: "For decades, researchers and doctors thought that anxiety and depression contributed to these problems. But our studies and others show that it may also be the other way around," Pasricha says.