Has your doctor recently told you to eat yoghurt while you were taking a course of antibiotics? Or perhaps you’ve used probiotics to help with a bout of irritable bowel syndrome? Well, soon you may be using probiotics (the bacteria commonly used to ferment milk products such as yoghurt) to improve your mood and general brain function.

It seems that a new study out of the Oppenheimer Family Center for Neurobiology of Stress, David Geffen School of Medicine, University of California Los Angeles provides the first evidence in humans that probiotics in the diet can affect brain activity.

Researchers found that they could change the activity of areas of the brain that control the processing of emotion and sensation in women if the women regularly ate probiotic-containing yoghurt.

The women underwent a brain MRI before and after they ate the yoghurt to measure resting brain activity and brain responses to an emotion-recognition task. The task involved the women looking at a series of pictures of people with angry or scared faces and matching them to other faces showing the same emotions. The researchers say they chose this task because studies in animals have linked changes in bowel flora to changes in mood and state-of-mind.

During the task, the group taking the yoghurt (containing probiotics) showed far lower activity in the area of the brain which processes and integrates internal body sensations, like those from the gut. These changes were not observed in the group that consumed the milk product without probiotics. What this may mean is that stomach conditions possibly brought on by psychological and emotional stimuli could potentially be tempered by controlling the gut environment.

That said, this is a small study, only in women, and the way in which the bacteria are creating their effects remains unclear so there is much work still to be done. In the meantime, those of us who enjoy a bit of yoghurt on our muesli will have to settle for the fact that we love the taste – and that makes us happy!