The impact of stress on mental health is widely discussed, but now scientists are beginning to look more specifically at the impact it can have on our physical wellness. While most people know stress can affect everything from your breathing to your menstrual cycle, a new study from Brigham Young University (BYU) indicates that stress may also play a large role in digestive and metabolic health — especially for women. The research was conducted by Laura Bridgewater, a BYU professor of microbiology and molecular biology, and was published in Nature Scientific Reports.
For the study, Bridgewater and her peers at Shanghai Jiao Tong University in China took two large groups of male and female mice, exposing half of each group to high-fat diets and stressors. Before exposing the animals to stress-inducing tests, Bridgewater collected samples of microbial DNA (aka, the bacteria in the stomach) to compare with samples taken at the end of the six week-long study. Though Bridgewater observed that the male mice had higher levels of anxiety and decreased activity when exposed to stress in comparison to the female mice, she found only female mice had harmful shifts or deviation in gut bacteria health. Bridgewater also discovered the unhealthy shift in the mice's gut bacteria was comparable to the effect junk food has on digestive health. Other studies have shown that fast food can cause a range of issues concerning your immune system, which is directly influenced by gut health.
"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," Bridgewater said in a press release. The scientists tested on mice, but their findings could have serious implications for humans and our physical health. “We sometimes think of stress as a purely psychological phenomenon, but it causes distinct physical changes," explained the BYU professor.
Bridgewater’s research is important because gut bacteria plays a crucial role in your digestive system, and can affect your overall health if it is imbalanced. Your stomach is an ecosystem (yes, really!) that can be rocked by stress, much like the Everglades or Amazon Rainforest can be damaged by natural or manmade disasters. Healthy gut bacteria has already been proven to be hugely important in maintaining your immune system, so it’s no wonder that when you are more stressed (and therefore, your gut bacteria is off) you seem to catch the flu easily. Gut bacteria is also linked to heart disease and cancer risk factors, so it’s extremely important to keep your gut healthy.
Moreover, Bridgewater’s discovery about physical health provides insight into mental health issues, especially how mental illness manifests in women. “In society, women tend to have higher rates of depression and anxiety, which are linked to stress,” says Bridgewater. “This study suggests that a possible source of the gender discrepancy may be the different ways gut microbiota [gut bacteria] responds to stress in males versus females.”
It is important to note that, while there is a common misconception that poor people eat more fast food (middle class Americans have been found to eat the most fast food on average), many people do not have the means to eat “healthy” food (aka, food that's good for your gut) all the time. However, Bridgewater’s study shows that reducing stress could be the key to digestive health issues, especially if you do not have wiggle room on your monthly budget to buy gut-healthy foods. If you are struggling with chronic acid reflux, or Irritable Bowel Syndrome, you don't necessarily need to buy expensive, probiotic drinks from Whole Foods to get your gut in check: you may find it helpful to incorporate stress-management skills, such as mindfulness, into your day-to-day life.
The BYU study is an important reminder that stress greatly affects our health and wellness, in more ways most of us realize. While it’s not possible to eat healthy foods all of the time — even if I could, I wouldn’t give up my McDonald’s french fries — it might be possible to improve your gut health just by managing your stress.