A new research reveals that probiotics found in natural yogurt could help boost a person's mood because they affect brain function. The results showed that women who ate the probiotic yoghurt had reduced activity in the part of the brain that handles aspects of cognition and emotion, while women who ate non-probiotic yoghurt or no dairy showed either no change or an increase in activity.
Previous studies have shown that beneficial bacteria affected the brains of rats but no research has confirmed that the same occurred in human brains.
The study found that those who ate probiotic yoghurt twice daily for a month showed altered brain function, both in resting brain activity and in response to an 'emotional attention task', which was designed to monitor how the brain responded to certain emotions, reports dailymail.co.uk.
It has also been known that the brain sends signals to the gut (stomach), which is why stress and other emotions can contribute to gastrointestinal symptoms.
"Our findings indicate that some of the contents of yogurt may actually change the way our brain responds to the environment," said Kirsten Tillisch of the University of California - Los Angeles's School of Medicine, who led the study.
"When we consider the implications of this work, the old sayings 'you are what you eat' and 'gut feelings' take on a new meaning," added Tillisch.
"Time and time again, we hear from patients that they never felt depressed or anxious until they started experiencing problems with their gut. Our study shows that the gut-brain connection is a two-way street," she said.
Tillisch's team recruited 36 women aged between 18 and 53 for the study.
They were assigned to one of three groups. One group ate a yogurt with live bacterial cultures containing probiotic strains twice a day for one month. Another ate a dairy product which contained no living bacteria, and the third was given no dairy products at all.
Emeran Mayer, who also worked on the study, said that what we eat alters the way our gut bacteria breaks down food.
He also suggested that specific probiotic strains in yogurt could have health benefits such as relieving anxiety, stress, and other mood symptoms over time.
"It is possible that changing the composition of gut bacteria could lead to treatments for chronic pain disorders as well as symptoms of brain conditions like autism, Parkinson's, and Alzheimer's disease," he said.