Gut feelings

Gut microbiome composition and diversity are related to human personality traits
HUMAN MICROBIOME JOURNAL

We’re just beginning to understand the connection between your gut bacteria and your brain, and boy does it look promising. Your microbiome–the 500-1,000 different species of bacteria in and around your body–is unique to you(!), and plays so many roles in your health that some docs say it’s the future of medicine.

We’ve known for years that these microbes help digest food and absorb nutrients. They help with immune system development, as well as vitamin and neurotransmitter production. To me, the most interesting connection we have with these little guys is known as the "microbiome-gut-brain axis.

Dr. Katerina Johnson, a researcher from the University of Oxford, checked in on how the variety of the microbiome might affect personality. Does the diversity of the bacterial species, she wondered, matter to mental health?

After analyzing stool samples from 655 adults, this study concluded that the specific types of bacteria, along with the degree of variety of bacteria in the microbiome, both play roles in behavioral traits. This includes the extreme seen in autism, to the more general seen in stress, negative mood, and sociability.

Having a larger social circle, for example, is related to a more diverse microbiome, which is associated with overall better health. Unfortunately for me, the study also found that people with higher stress or anxiety had a lower microbiome diversity. People who reported poor sleep habits also had a less diverse microbiome.

Put differently, microbiome diversity matters when it comes to both our physical and mental health. As for how we can diversify, this study showed that we're mostly in control. Higher diversity is associated with people who were breast-fed as children, as well as people who eat a diet rich in probiotics (fermented foods) and prebiotics (banana, legumes, whole grains, asparagus, onions, etc.). Interestingly, diet seems key here as Dr. Johnson noted that this wasn’t the case with people who were supplementing with probiotics.

TAKEAWAY
Personality is partially inherited, but also highly impacted by your external environment. The 100 trillion microorganisms in your gut help shape your unique personality, adding mental health to the microbiome's impressive list of responsibilities. Diversity is one way to measure the condition of the microbiome. Having a wider diversity of bacteria can be achieved through socialization as well as pre- and probiotic foods, not supplements.