Gut microbes tied to psychopathic traits in preliminary study

A small, non-peer-reviewed study from the University of Porto reports a correlational link between specific gut and oral bacteria (Allisonella, Prevotella, and C. evryensis) and psychopathic traits in 200 adults. The researchers caution that the study is correlational with a small sample and potential biases, so causality cannot be established and results may vary by geography or self-report biases; more research is needed to explore how the gut microbiome might influence extreme behavior, if at all.