Stress just as harmful as junk food to health in females, researchers say

The impact of stress can be just as damaging to health as a high-calorie diet in female mice, according to research.
A US study has found exposure to stress has a similar effect on the gut’s bacteria to eating a junk food diet.
The findings could be an important breakthrough in understanding more about why type 2 diabetes develops. Previous research has indicated a gut bacteria imbalance can sometimes prompt insulin resistance which leads to the condition.
Lead author Professor Laura Bridgewater, who is professor of microbiology and molecular biology at Brigham Young University (BYU), said: “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. We sometimes think of stress as a purely psychological phenomeno, but it causes distinct physical changes.”
Working alongside researchers from the Shanghai Jiao Tong University in China the team split the mice into groups according to gender. This was because they wanted to determine whether there was a difference between males and females in the way their bodies reacted to a poor diet and stress exposure.
All the animals were fed a high-calorie diet for a set period of time and then exposed to stress across 18 days. Using fecal deposits, the researchers were able to monitor the gut’s activity. The animals’ anxiety levels were recorded by monitoring their activity levels and where they moved to in an open space.
The researchers found anxiety levels were higher in the males on the high-fat diet than the females, and “decreased activity” in response to stress was also recorded. But it was only in the female mice which stress seemed to affect the gut bacteria mirroring similar patterns which would be expected in the gut of obese mice.
Professor Bridgewater said: “In society, women tend to have higher rates of depression and anxiety, which are linked to stress. This study suggests that a possible source of the gender discrepancy may be the different ways gut microbiota responds to stress in males and females.”
The researchers said their findings reveal a “distinct gender differences in the impacts of obesity and stress on anxiety-like behaviors, activity levels, and composition of the gut microbiota”.
They concluded: “These results suggest the importance of considering gender as a biological variable in studies on the role of gut microbiota in obesity-related mood disorders.”
The findings have been published in the Nature journal.