Health & Environment

What You Eat May Help Shape Your Personality

New research shows distinct bacteria and metabolomes in the gut are associated with personality traits.
By Tim Schnettler, Texas A&M University School of Public Health March 29, 2022

woman dining outdoors biting into a hamburger
What you eat determines the bacteria and the microbiome in your gut — which researchers have now linked to personality and mood.



A recent study that includes researchers at the Texas A&M University School of Public Health has taken a step toward showing there may be some truth to the old adage “you are what you eat.”

The study, which was published recently in the journal Nutrients, suggests there are distinct bacteria and metabolomes associated with each personality trait.

“This reinforces many of the public health concepts related to nutrition and health,” said Matthew Lee Smith, associate professor in the Department of Environmental and Occupational Health and one of the researchers on the study. “Gut microbiome may be influencing the way you are, not just the way you are today. These findings are more suggestive than definitive, but they have contributed to our understanding of what gut health can do and how it makes people feel.”

The research team studied the correlation between mental energy (ME), mental fatigue (MF), physical energy (PE), physical fatigue (PF) and the gut microbiome. It found that bacteria and metabolome associated with metabolism were associated with either mental or physical energy, while bacteria associated with inflammation were associated with mental or physical fatigue.

“What you eat determines the bacteria and the microbiome in your gut,” said Ali Boolani, associate professor in the Department of Physical Therapy at Clarkson University and lead author on the study. “With this study, we have made an exploratory link between a person’s microbiome and their mood.”

Fatigue is a known problem that contributes to poor work and school performance and can be attributed to many diseases and disorders among middle-aged and older adults, but it is a poorly understood problem.

When someone says they are fatigued, more often than not it is chalked up to a lack of energy. However, more recent evidence has shown that the two are not as connected, as we have previously been led to believe. Fatigue and energy are distinct moods, not necessarily opposites of one another.

One area that has been shown to contribute to fatigue is nutrition, or a lack thereof. Food is the biggest source of energy for individuals and a healthy diet can help to combat some of the pitfalls associated with fatigue. However, it is not the only factor.

The research team studied a subset of individuals from a larger study that investigated the gut microbiome. Participants completed a brief survey that was used to identify potential correlations between gut microbiota and mental and physical energy and fatigue.

They found that the four traits, ME, MF, PE and PF have unique, but overlapping gut bacteria profiles, suggesting a need to further explore the role of gut microbiota to understand long-standing feelings of energy and fatigue.

“We know that energy and fatigue can be influenced by so many things like what you eat, your physical activity, your sleep, your chronic conditions or the medications you take for these conditions,” Smith said. “Understanding how nutrition and malnutrition are linked to fatigue and energy is important because falls, chronic fatigue and low-energy can diminish the health and quality of life for older adults living with chronic conditions.

“I think part of the fun here is looking at some of these relationships and being able to better see this interplay and how what you eat can influence these things,” he said.

In addition to Smith and Boolani, the research team includes Lauri Byerley, Christopher Taylor and Meng Lou from Louisiana State University Health Sciences Center, New Orleans; Courtney Christopher, Hector Castro and Shawn Campagna from University of Tennessee, Knoxville; Kristin Ondorak and Karyn Gallivan from American Public University System; and Scot E. Dowd from Molecular Research LP.

“This study is a strong example of team science with a multidisciplinary collection of scholars,” Smith said. “The team represents physical therapy, biology, physiology, chemistry, microbiology and public health. This gives multiple perspectives that can work collectively to interpret and report scientific findings.”

This article by Tim Schnettler originally appeared on Vital Record.

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