A recent study has found a link between the composition of the gut and oral microbiome and psychopathic traits, adding a new dimension to the influence of bacteria living inside our bodies on shaping behavior and identity.
After previous research demonstrated that gut microbes can influence our emotions and fear response, attention is now turning to their potential role in more complex personality traits, such as lack of empathy, impulsivity, and selfishness—traits that characterize psychopathic personality, the biological basis of which remains largely mysterious.
In a study published in the journal Translational Psychiatry, researcher Carolina Costa from the University of Porto in Portugal led a scientific team that studied 200 healthy adults. They were asked to fill out a questionnaire to measure psychopathic traits, and they also provided blood, saliva, and stool samples for analysis of the bacterial composition. Surprisingly, the comparison between the participants revealed a clear correlation between the abundance of three specific types of bacteria and the high indicators of these traits. These bacteria are Allisonella, Prevotella, and Cloacibacillus evryensis, while a fourth type, Treponema vincentii, was associated with a decrease in these indicators.
Researchers believe that these bacteria may influence psychopathic behavior through multiple biological mechanisms. Some promote inflammation associated with anxiety and depression, some affect emotional processing, and others may produce chemicals such as gamma-aminobutyric acid (GABA), which plays a role in regulating impulse control. However, they emphasize that the current findings only show correlations and do not prove a causal relationship, meaning that these bacteria may be a biological marker associated with, rather than a direct cause of, psychopathic traits.
Although the results have not yet been peer-reviewed, the research team believes this is the first time this link has been explored, opening the door to future research that could change our understanding of the biological basis of personality, and may even one day help doctors identify people most susceptible to these tendencies or develop new intervention strategies based on microbiome modification. However, there is still a long way to go to fully understand this complex relationship.
This study adds to a growing body of evidence that the microbiome is not just a collection of bacteria living in our bodies, but an active partner in shaping who we are, and its influence extends beyond digestion and immunity to encompass the most complex aspects of our personalities, redefining the boundaries between biology and psychology.
