Experts believe that the probiotics found in yoghurt improve people's mood, since they have an effect on the function of the brain. Past studies confirmed that these bacteria affected the minds of rodents but so far it had not been proven that they affected people as well.
The experts who carried out the study determined that the people who ate yoghurt twice a day for the duration of a month had an altered brain activity.
This change was observed in the reactions to tasks, which were related to emotional attention, with the brain being monitored in how it reacted to emotions, as well as in times of rest.
Of symbiotic intestinal bacteria, it is known that they protect against a series of diseases, for they boost the immune system, ease the maintaining of normal blood pressure, aid in digestion. These bacteria are actually a complex ecosystem of microorganisms that live in the human digestive system.
It is known that during stress or some other emotion, the brain sends signals to the intestines, which may lead to gastrointestinal problems. A study proved that the signals actually went in the opposite direction.
36 women, who were of normal weight and between the ages of 18 and 53, took part in the study. It was carried out by experts from UCLA, headed by Dr. Kirsten Tillisch.
The women were divided into 3 groups of 12 - in the first group, the participants ate yoghurt with probiotic strains such as Streptococcus thermophiles, Lactobacillus bulgaricus and Bifidobacterium animalis twice a day.
The second group consumed yoghurt without any live bacteria, and in the third group, the women did not eat dairy products at all. The women were analyzed before the study, as well as after its conclusion.
In each session, the experts began with a 5 min. scan of the brain at rest, while the ladies lied down with their eyes closed. Then the women were asked to complete a task related to their emotional attention.
The brain was scanned during this task also, while the ladies paired different faces expressing anger and fear on a computer screen with other faces that appeared.
The results showed that the women from the first group had a decreased activity in the part of the brain that had to do with their sense of touch. The ladies from the group that ate non-probiotic yoghurt, as well as the women from the 3rd group, had no change in that part of the brain.
Scientists hope to soon discover the signals from intestinal bacteria that lead to this change in brain function.