It starts in the gut: Stress and autoimmune disease can be traced back to your microbiome

Several recent studies have pointed to the surprisingly big role your gut microbiome plays in a host of physical and mental illnesses, and now it’s being used to explain the link between stress and autoimmune disease.

Diseases like lupus and rheumatoid arthritis are considered autoimmune diseases as they involve your immune system attacking your body’s own cells, tissues and organs as though they were dangerous viruses or bacteria. Scientists have long known that stress was a risk factor for this type of illness, but they weren’t certain why until now.

Scientists from Israel’s Bar Ilan University have discovered that the gut bacteria found in mice actually work to raise the number of a type of immune cell involved in autoimmunity known as effector T helper cells in response to stress.

The scientists divided mice into two groups: a control group and one that was subjected to social stress in the form of 10 days of encounters with dominant, aggressive mice. Those in the latter group had more Dehalobacterium and Bilophila than the mice in the control group. Higher levels of these same gut bacteria have been seen in people suffering from the autoimmune disease multiple sclerosis.

The researchers found that not only did persistent social stress change the expression of genes seen in the gut bacteria of the mice, but it also altered their composition. The biggest changes in the genes enabled bacteria to grow, move around, and communicate with their host. This allows them to make their way outside of the gut and travel to places like lymph nodes, spurring an immune repose. They noted higher amounts of pathogenic bacteria and effector T cells within the gut lymph nodes of the mice who were in the group subjected to stress.

Therefore, they believe a chain of events occurs when mice are exposed to stress. This stress changes their gut bacteria, which in turn changes immune cells in a way that raises the risk of an autoimmune attack.

Autoimmune diseases are difficult to study

Although further studies are needed, this study is a step in the right direction when it comes to unlocking the mechanism behind a largely mysterious category of illnesses. Right now, more than 50 million Americans are suffering from an autoimmune disease, and many times, the cause simply isn’t clear.

Although the risk of certain diseases may be inherited, it’s the complex interactions between the environment and genes that experts believe influence a person’s chances of developing such an illness.

These diseases can be tricky to study because symptoms can vary significantly, even among those suffering from the same disease. For example, multiple sclerosis is an autoimmune disease that sees the immune system attacking the protective protein on the body’s nerves. Its symptoms are unpredictable and vary wildly in severity, although it often begins with vision problems before progressing to coordination issues.

A different study backs up the link between stress and autoimmune disorders. In research that was published in the Journal of the American Medical Association last year, scientists analyzed more than 100,000 people who had been diagnosed with a stress-related disorder and compared their tendency to later develop an autoimmune disease with the chances of their non-stressed siblings developing such an illness.

They discovered that people with a stress-related disorder were not only more likely to be diagnosed with autoimmune disorders, but they also had a higher likelihood of developing multiple illnesses within this category.

Unfortunately, stress can be hard to manage. Some of the best ways to fight it include meditation, consuming a clean diet, and exercising regularly. While stress isn’t fun to experience on its own, the illnesses it can spur are even more upsetting, so it’s important to get it under control.

Sources for this article include:

MedicalNewsToday.com

Health.Harvard.edu

JAMANetwork.com