The featured proof-of-concept study, conducted by researchers at UCLA, found that probiotics (beneficial bacteria) actually altered participants’ brain function.
The study enlisted 36 women between the ages of 18 and 55 who were divided into three groups:
· The treatment group ate yogurt containing several probiotics thought to have a beneficial impact on intestinal health, twice a day for one month
· Another group ate a “sham” product that looked and tasted like the yogurt but contained no probiotics
· Control group ate no product at all
Before and after the four-week study, participants underwent functional magnetic resonance imaging (fMRI) scans, both while in a state of rest, and in response to an “emotion-recognition task.”
For the latter, the women were shown a series of pictures of people with angry or frightened faces, which they had to match to other faces showing the same emotions.
“This task, designed to measure the engagement of affective and cognitive brain regions in response to a visual stimulus, was chosen because previous research in animals had linked changes in gut flora to changes in affective behaviors,” the researchers explained.
Compared to the controls, the women who consumed probiotic yogurt had decreased activity in two brain regions that control central processing of emotion and sensation:
· The insular cortex (insula), which plays a role in functions typically linked to emotion (including perception, motor control, self-awareness, cognitive functioning, and interpersonal experience) and the regulation of your body’s homeostasis, and
· The somatosensory cortex, which plays a role in your body’s ability to interpret a wide variety of sensations
During the resting brain scan, the treatment group also showed greater connectivity between a region known as the ‘periaqueductal grey’ and areas of the prefrontal cortex associated with cognition. In contrast, the control group showed greater connectivity of the periaqueductal grey to emotion- and sensation-related regions.
The fact that this study showed any improvement at all is remarkable, considering they used commercial yogurt preparations that are notoriously unhealthy; loaded with artificial sweeteners, colors, flavorings, and sugar. Most importantly, the vast majority of commercial yogurts have clinically insignificant levels of beneficial bacteria. Clearly, you would be far better off making your own yogurt from raw milk—especially if you’re seeking to address depression through dietary interventions.
