stress worse than junk food diet
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Research shows that stress has a similar impact on digestive health as a high-fat diet.
A diet full of junk food isn't the only thing that can have a negative impact on the digestive system.

Researchers from Brigham Young University (BYU) found that stress could be just as harmful to the human body as a nutritionally poor diet.

The scientists discovered that when female mice were exposed to stress, their gut microbiota-the microorganisms vital to digestive and metabolic health-morphed to look like the mice had been eating a high-fat diet.

"Stress can be harmful in a lot of ways but this research is novel in that it ties stress to female-specific changes in the gut microbiota," BYU professor of microbiology and molecular biology Laura Bridgewater said in a statement. "We sometimes think of stress as a purely psychological phenomenon but it causes distinct physical changes."

The team performed an experiment on a large group of eight-week old mice and exposed half of the males and half of the females to a high-fat diet. After 16 weeks, all of the mice were exposed to mild stress over the course of 18 days.

Microbial DNA from the mice's fecal pellets were extracted before and after the stress to test how the gut microbiota was impacted. They also measured mouse anxiety based on how much and where the mice traveled in an open field arena.

After analyzing the results, the researchers learned males on a high-fat diet exhibited more anxiety than females on the high-fat diet. Males on the high-fat diet also showed decreased activity in response to stress.

However, stress only caused the gut microbiota composition to shift in female mice as if they were on a high-fat diet.

"In society, women tend to have higher rates of depression and anxiety, which are linked to stress," Bridgewater said. "This study suggests that a possible source of the gender discrepancy may be the different ways gut microbiota responds to stress in males vs. females."

The study was published in Scientific Reports.