For the first time, scientists have found evidence that bacteria ingested in food can affect the brain. A study, which was conducted by the team at UCLA, revealed that women who consumed good bacteria through yoghurt showed altered brain function during the resting state and in response to an emotion recognition task.
The study also confirms what scientists knew all along – the brain sends signals to the gut. This is why stress and other emotional upsets can cause problems with the gastrointestinal system. However, researchers have now found that signals also travel in the opposite direction – from the gut to the brain.
The researchers found that the women who consumed yoghurt showed a decrease in the activity of both the insula and the somatosensory cortex. The insula processes and integrates internal body sensations, including those from the gut. The somatosensory cortex is involved during emotional reactivity.
During the resting state, those who consumed probiotics showed improved connectivity between a major brainstem region (the periaqueductal grey) and the cognition-assisted areas of the prefrontal cortex. In response to the task, the probiotic group demonstrated the engagement of a widespread network in the brain that includes emotion, cognition and sensory-related areas.
This study raises the question of how courses of antibiotics may affect not only the gut, but the brain. Significant amounts of antibiotics are frequently used in neo-natal intensive care units and it is unknown how this treatment may affect an infant’s long term brain development, when their indigenous gut flora is suppressed over a period of time.
This discovery raises significant implications for future research that could lead to the development of new dietary interventions to improve brain function. The researchers are seeking to determine the specific chemicals produced by gut bacteria that may be triggering the transmission of signals to the brain.
Going forward, studies will investigate what effect gastrointestinal problems such as bloating, altered bowel movements, and abdominal pain have on changes in the brain response. This is an exciting area of research and should provide us with better information about the effect that gut flora has on diseases associated with the brain, like Parkinson’s, Alzheimer’s and chronic pain conditions.
Source: Champeau. R. Changing gut through diet affects brain function, UCLA study shows. UCLA, May 28 2013.