Stress can alter the digestive system, not just the mind and spirit.
We know that fries, chips, burgers and soda are junk food, to be eaten sparingly. And we know that stress is harmful to our bodies. A new study shows that stress can literally alter gut microbiota—the microbe population in the gastrointestinal tract—in much the same ways as a high-fat diet.
The research was published in Nature Scientific Reports, and was conducted by scientists at Brigham Young University and Shanghai Jiao Tong University in China. Laura Bridgewater, a professor of microbiology and molecular biology at BYU, and the associate dean of BYU College of Life Sciences, led the team. They worked with rodents, exposing 8-week-old mice (deemed as mice adults in the science world) to a high-fat diet. Then, after 16 weeks, they were returned to a normal diet and exposed to mild stress. How do you mildly stress a mouse, by the way? Have them refinance a mouse mortgage? Spend holidays with the mouse in-laws? But I digress. The team judged how the gut microbiota was changing for the mice, by extracting microbial DNA from the mouse poop. Results: The male mice had exhibited more signs of anxiety while on the high-fat diet, but once it was stress only, it was the female mice that had their gut microbes shifting as if they were still on the 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,” wrote Bridgewater in the study. “We sometimes think of stress as a purely psychological phenomenon, but it causes distinct physical changes.”
While the study was only conducted on mice, not humans, Bridgewater and her team feel there may be a takeaway for humans. “In society, women tend to have higher rates of depression and anxiety, which are linked to stress,” Bridgewater wrote. “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.”