According to research done by a group of UCLA, brain function can be affected by bacteria in our food. In this study, they've involved healthy women who had shown that their brain functions have changed after consuming probiotics on yogurt.
Dr. Kirsten Tillisch, an associate professor of medicine at UCLA's David Geffen School of Medicine and lead author of the study, said:
"... Our findings indicate that some of the contents of yogurt may actually change the way our brain responds to the environment."
Studies have already established the brain sending signals to the gut, which is why there are stress-related gastrointestinal problems.
Thirty-six women between the ages of 18 and 55 took part in the study. They were split into three different groups: Group one ate a yogurt containing a mix of several probiotics twice a day for four weeks. Group two consumed a dairy product that contained no probiotics and group three ate no dairy or probiotic product at all.
The researches conducted scans before and after the 4 week period of the study. The women were asked to look at angry or frightened people in pictures in order to measure the affective and cognitive brain regions' response to visual stimulus.
The researches have found that during the emotional reactivity task, the women who ate probiotic yogurt had experienced less activity in the part of the brain that processes internal body sensations. This is the insula and the somatosensory cortex.
Also, the women who ate yogurt with probiotics had shown the activity decrease in emotion-, cognition- and sensory-related areas of the brain compared to those in the two other groups.
In these women's resting state, those who were eating probiotic yogurt had shown more connectivity between periaqueductal grey and areas of the prefrontal cortex responsible for cognition or the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses.
The study's senior author, Dr. Emeran Mayer, a professor of medicine, physiology, and psychiatry at the David Geffen School of Medicine at UCLA said that because of these signals are sent from the intestine to the brain can be influenced by dietary change, it will hopefully encourage more studies on the topic of digestive and mental disorders. According to Mayer, "There are studies showing that what we eat can alter the composition and products of the gut flora ''" in particular, that people with high-vegetable, fiber-based diets have a different composition of their microbiota or the gut environment than people who eat the more typical. [The] Western diet that is high in fat and carbohydrates. Now we know that this has an effect not only on the metabolism but also affects brain function."
The researchers are now focusing on finding the chemicals that send a signal to the brain. They also want to find out if gastrointestinal symptoms such as abdominal pain, bloating, and altered bowel movements have a connection to variations in brain response.
The researches hope that in the future they will be able to manipulate intestinal content to treat brain-related diseases like Alzheimer's or Parkinson's.