Gut Microbiome Composition Linked to Human Behavior
Gut Microbiome Composition Linked to Human Behavior

Gut Microbiome Composition Linked to Human Behavior

A study uncovers connections between the bacteria in our guts and our social lives.

Amy Schleunes
Amy Schleunes

A former intern at The Scientist, Amy studied neurobiology at Cornell University and later earned her MFA in creative writing from the University of Iowa. She is a Los...

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Jun 1, 2020

ABOVE: A study uncovers connections between gut microbes such as Bifidobacterium (illustrated above) and people’s social lives.
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The paper
K.V.-A. Johnson, “Gut microbiome composition and diversity are related to human personality traits,” J Hu Mic, 15:100069, 2020.

Researchers have shown that fecal transplants in mice can change the animals’ temperaments. Several studies have also linked the human microbiome to psychiatric illnesses, including autism and depression. But to date, few experiments have considered the microbiome of the general population and whether variations in gut bacteria are associated with personality traits, says microbiome-gut-brain axis researcher Katerina Johnson of Oxford University.

In a recent study, Johnson analyzed gut microbiome data obtained from stool samples of 655 individuals, along with survey-based information about their personality and behavior, health and lifestyle, dietary habits, and sociodemographics. She found that people who have larger social networks are more likely to have greater gut microbiome diversity, which research indicates is associated with both gut health and general health. The analysis also showed that “sociable people tend to have a higher abundance of certain types of gut bacteria” that have been found to be less abundant in people with autism, Johnson says. She adds that her analysis also identified bacteria found in lower abundances in sociable people that had previously been found to be highly abundant in autistic people.

She notes that further research is needed to directly investigate any effect that gut bacteria may have on human behavior, but ultimately, she says, these findings and follow-up research “might help with the development of new therapies for conditions like autism.” 

Gerard Clarke, a microbiome researcher at University College Cork in Ireland who was not involved in the study, tells The Scientist in an email that we can’t definitively say whether “these very interesting associations manifest in biological or physiological terms of relevance to social behavior,” but that the paper yields “a number of important clues as to who might be involved in the conversation between the gut and the brain.”