What upsets your stomach? If you overeat, you can end up with digestive issues and a classic stomach ache. If you have issues with certain foods like regular milk because you lack the enzyme lactaid, you can end up with stomach discomfort. Eat too close to bedtime and you may end up with a stomach ache or indigestion in the middle of the night. Eating too many fried, fatty, or junk foods can cause your stomach to act up on a regular basis. Typically, you know the cause of your stomach discomfort right when it happens.
There are also “silent changes” that can occur in your digestive tract that impact your health. Research has confirmed that a junk-filled diet can instigate changes in the microbe balance of your gut. That shift in microbe balance can fuel disease. A new study suggests that stress can instigate changes in gut bacteria and those microbe shifts can be quite similar to those prompted by a high-fat diet.
The research, published in Nature’s “Scientific Reports,” looked at what happened to mice when they were exposed to stress, specifically looking for any changes in the gut microbiota. Gut microbes are central to digestive and metabolic health and a very delicate balance exists in humans and most animals. The researchers wanted to see if stress, which can be harmful to psychological health, could also have a physical impact.
The researchers gathered a large group of eight-week-old mice, both male and female, and exposed half to a high-fat diet. After 16 weeks, all of the mice (both groups) were exposed to mild stress for 18 days. Stress was measured by seeing how much and where the mice traveled in open field areas. Researchers then extracted DNA from the animals’ fecal pellets to see how gut microbes were affected. The researchers discovered that findings were gender-specific.
Male mice fed high-fat meals exhibited higher levels of anxiety, compared to the female mice that had eaten a high-fat diet. Obese male mice eating a high-fat diet also showed less activity in response to stress exposure. Only in female mice was “just stress exposure” responsible for gut microbe changes, and the shift was similar to the changes caused by a high-fat diet. In fact, lean female mice that were stressed had a shift in microbes that was similar to the microbiome seen traditionally in obese mice.
The researchers point to our current society, where women are observed to have higher rates of depression and anxiety, which are linked to stress. So it would be especially important to identify stress levels, if they have the potential to also shift gut microbes in the same way that an unhealthy diet does.
Major life stressors, especially those involved in interpersonal stress and social rejection, are strong risk factors for depression. Chronic psychological stress is associated with greater risk of heart disease and infectious diseases. In this case, the chronic stress seems to instigate general inflammation due to the dampening effect that stress has on our immune system. It may well be that stress-induced inflammation instigated the shift in the gut microbiota of the female mice.
The gut microbe balance discussion has been trending for some time. Researchers and health professionals are just beginning to realize the vast influence that gut microbes have on the human body and especially on health. Biotech companies are beginning to compete to develop drugs using “bugs as drugs” to fight cancer. Given the influence that good gut microbes have on health and the immune system, these companies believe that supporting the good gut bacteria will likely help patients to have optimal response to immunotherapy cancer treatments.
Changing one’s dietary habits can directly influence gut microbes, and over time, help to restore the healthy balance of the different bacteria in the gut. If this animal study has human implications, it becomes even more important to reduce overall stress — since in addition to causing psychological distress, it may raise the risk of an undesirable shift in gut microbes.
Anyone can benefit from lifestyle steps that support health, limit stress, and preserve healthy gut microbe balance:
- Have 10 servings of fruits and vegetables daily
- Limit consumption of highly processed foods
- Choose high-fiber whole grains
- Limit red meat consumption
- Consume a variety of plant-based proteins
- Limit sugar, salt, and unhealthy fats
- Limit fried foods, sugary beverages
- Include probiotic-rich foods including natural yogurt, kefir, sauerkraut, kimchi, miso, fermented vegetables
- Manage stress
- Exercise daily
- Get sufficient sleep
- Talk to your healthcare professional about taking probiotics on a regular basis.
- Review your current medications, including antacids with your doctor since some medications (like antibiotics) can shift microbiome balance.
- Always take probiotics during a course of antibiotics and continue for several days after completing the drug therapy.