Scientists have long known that the brain sends signals to the gut, a process that reveals why stress, for example, can express itself through gastrointestinal symptoms. But it wasn’t until 2013, when researchers at the UCLA uncovered the first evidence that the signal can go the other way as well: from gut to brain.
“Many of us have a container of yogurt in our refrigerator that we may eat for enjoyment, for calcium or because we think it might help our health in other ways,” said Kirsten Tillisch, an associate professor of medicine in the digestive diseases division at UCLA’s David Geffen School of Medicine and lead author of the study. “When we consider the implications of this work, the old sayings ‘you are what you eat’ and ‘gut feelings’ take on new meaning.”
The study is just one of many that comprise a growing body of research examining how gut flora, and the fermented foods that contain it, such as yogurt, impacts mood. Since 2008, when the U.S. National Institutes of Health launched the Human Microbiome Project, a five-year initiative to identify and characterize the microorganisms in both healthy and diseased humans, “the profound appreciation for the influence of such organisms has grown rapidly with each passing year,” writes Peter Andrey Smith in a New York Times Magazine article in June.
These helpful bacteria like probiotics do a lot for us, from extracting energy from the fermentation of undigested carbohydrates and increasing the growth of intestinal epithelial cells to synthesizing vitamins and suppressing the growth of pathogens.
Now a new study recently published in the journal Food Research International indicates that there may be other, completely different reasons why yogurt has the power to make us happy, and it has to do with the way expectation impacts mood and possibly even scent. read more..