Within the invisible ecosystem of the human body, trillions of microbes have long been understood to shape mood and cognition — but a new study from the University of Porto now suggests their influence may extend into the architecture of personality itself. Researchers analyzing 200 healthy adults found that specific gut and oral bacteria correlate with subclinical psychopathic traits such as impulsivity, callousness, and diminished empathy. The work is preliminary and correlation is not causation, yet it quietly challenges the long-held assumption that psychopathy is a story told only by the