Research has shown that the brain sends signals to the gut via the brain – gut axis. This is why things like stress and other emotions can contribute to gastrointestinal symptoms.
But can it work the other way? Can what you eat affect the brain? UCLA researchers have evidence that bacteria ingested in food can affect brain function. In their study, they found that women who regularly consumed probiotics, through yogurt showed altered brain function. This association demonstrated that changing the bacteria environment of the gut can affect the brain, potentially improving brain function and impacting emotion.
Another 2016 study found that workers who ate 100 grams of probiotic yogurt a day or took a daily probiotic capsule, experienced less stress, depression, and anxiety than those who did not.