Gut Bacteria Could Play a Part in Your Personality

Dr. Katerina Johnson of Oxford University is taking the old adage “You are what you eat” to a whole new level. In a study recently published in the Human Microbiome Journal Johnson reported finding “correlations between gut ecology and certain personality traits,” IFLScience.com reports. 

To conduct this study, Johnson collected fecal samples from 655 people around the world and recorded the frequency of different bacterial families. She also asked these same participants to fill out a questionnaire that asked them questions about their lifestyles and personalities. Whether the gut bacteria shaped an individual’s personality or vice versa, couldn’t be conclusively determined in this study, in certain situations the causality seems rather clear. 

For example, Johnson found that individuals who were breastfed as children had a more diverse gut microbiome than those raised on formula. The same could be said for those who like trying new foods, have a diet consisting of foods with naturally occurring probiotics, or have a wide social network. Johnson even found that a bacteria associated with autism showed a correlation with sociability in neurotypical people. 

While this is the first study to find a link between sociability and gut diversity in humans, previous research has focused on similar links in animals. 

“It was found that if you colonize an aggressive mouse with the gut bacteria of a shy mouse, the temperament of the mouse becomes more similar to the individual from whom they received the gut bacterial transplant,” Johnson told IFLScience.com. “Therefore in terms of personality traits, it is a credible hypothesis that gut microbes may play a causal role.”