Archive · 14 Aug 2026
Gut Bacteria Linked to Psychopathic Traits, New Study Finds
Inside your tummy live tiny living things called bacteria.
Scientists are learning that these bacteria talk to your brain.
A new study looked at 200 grown-ups.
They asked questions about feelings and behaviour to measure something called psychopathic traits.
Psychopathic traits are things like having less empathy and being impulsive, but having some does not mean someone is bad.
The scientists also looked at poop, spit and blood samples.
They found that people with more psychopathic traits had different kinds of bacteria in their bodies.
Some bacteria, like Allisonella and Prevotella, were found more often in people with higher scores.
But this does not mean the bacteria make someone a psychopath.
It only means the two things are linked, and we need more studies to understand why.
A study published in Translational Psychiatry examined 200 adults and found associations between certain gut and oral bacteria and higher scores for psychopathic traits.
Bacteria including Allisonella, Prevotella and Cloacibacillus evryensis were strongly associated with higher psychopathy scores, while Treponema vincentii showed a negative association.
Fecal levels of glucose and taurine differed between groups and were positively associated with psychopathy scores.
The study was observational and cross-sectional, so researchers could identify associations but could not determine whether gut bacteria cause psychopathic traits.
Researchers noted that microbiota-brain communication works in both directions, and psychopathy-linked factors such as eating behaviours and hormonal differences could shape gut microbiota.
- Who
- Researchers studying 200 adults who completed questionnaires measuring psychopathic traits, empathy and anxiety, and provided stool, saliva and blood samples
- What
- A study found that certain gut and oral bacteria and some metabolites were associated with higher scores for subclinical psychopathic traits
- When
- Not specified in the article; the research is described as new and was published in the journal Translational Psychiatry
- Where
- Study location not specified in the article; findings were published in the journal Translational Psychiatry
- Why
- To investigate whether the composition of gut and oral microbiota is associated with subclinical psychopathic personality traits
- Study venue
- Journal Translational Psychiatry
- Participants
- 200 adults
- Samples analysed
- Stool, saliva and blood
- Bacteria strongly associated with higher psychopathy scores
- Allisonella, Prevotella, Cloacibacillus evryensis
- Bacteria negatively associated
- Treponema vincentii
- Metabolites positively associated
- Fecal glucose and taurine
- Study design
- Observational, cross-sectional
- Key limitation
- Correlational findings; causality cannot be established due to bidirectional microbiota-brain communication