A new study suggests a possible association between the balance of microorganisms in the gut and certain personality traits linked to psychopathy. Researchers examined data from 200 adults who completed questionnaires measuring subclinical psychopathic traits, along with samples of blood, saliva and feces. The analysis found no overall difference in microbial diversity related to these traits. However, participants with higher psychopathy scores showed greater abundance of three bacterial types: Allisonella, Prevotella and C. evryensis. One species, T. vincentii, appeared less common in this group. The team noted that Allisonella has previously been connected to inflammation, which is sometimes observed in psychiatric conditions. Prevotella has been associated in other work with variations in brain areas involved in emotion and attention. Levels of glucose and taurine in fecal samples also differed and correlated with the trait scores. The authors caution that the study is correlational, the sample was modest, and self-reported measures can introduce bias. They add that the relationship could run in either direction, with behavior or diet potentially shaping the microbiome rather than the reverse. Further research is required to clarify any causal mechanisms.
