Gut microbiome and personality

[Otto Kretschmer]

Has gut microbiome been linked to personality?

In particular, I have a strongly unbalanced personality with very high Neuroticism and very low Extraversion... I wonder if getting an FMT from someone with a favorable Personality profile might reverse those tendencies? I'd like to turn into a fearless, extroverted individual.

 

[Michael Harrop]

https://humanmicrobiome.info/brain/?h=personality#fmt

Correlation between gut microbiota and personality in adults: A cross-sectional study (2017): https://www.sciencedirect.com/science/article/pii/S0889159117305536

Gut microbiome composition and diversity are related to human personality traits (Mar 2020) https://www.sciencedirect.com/science/article/pii/S2452231719300181 - https://www.ox.ac.uk/news/2020-01-23-gut-bacteria-linked-personality


There are certainly causative links to personality traits. From the first link:

"It is now clear that the gut microbiota contributes significantly to the traits of humans as much as our genes, especially in the case of atherosclerosis, hypertension, obesity, diabetes, metabolic syndrome, inflammatory bowel disease (IBD), gastrointestinal tract malignancies, hepatic encephalopathy, allergies, behavior, intelligence, autism, neurological diseases, and psychological diseases. It has also been found that alteration of the composition of the gut microbiota in its host affects the behavior, intelligence, mood, autism, psychology, and migraines of its host through the gut-brain axis." (2018): https://www.frontiersin.org/articles/10.3389/fmicb.2018.01510/full

 

[Otto Kretschmer]

@Michael Harrop have you experienced significant changes in personality as a consequence of FMT?

 

[Michael Harrop]

That was something I was curious and concerned about when I started out looking for a donor. Overall, FMT does not transfer personality, other than making you a better or worse version of yourself. It can certainly cause changes to "character traits", but largely only in so much as improving or worsening your general function. IE: if you have bipolar disorder and then cure it. Or if you use a bad donor and it worsens your cognitive function.

 

[Otto Kretschmer]

@Michael Harrop I have high Neuroticism. Do you think I could significantly lower the level of this trait if I get a successful FMT of someone who is low on Neuroticism?

Research shows there is a clear correlation between gut microbiome and Big Five personality traits. For example this 2024 study https://www.sciencedirect.com/science/article/abs/pii/S0278584623001720

 

[Michael Harrop]

Do you think I could significantly lower the level of this trait

Yes.

if I get a successful FMT of someone who is low on Neuroticism?

I don't think that's a valid way to go about FMT. "I'm high in X so find a donor low in X". Rather, look for a donor with an eubiotic, disease-resistant, unperturbed microbiome. People with all sorts of disorders and diseases would all benefit from the same "super-donor".