Lupus May Affect Gut Bacteria

In the last few years, there has been a lot of research on how gut health affects people. Doctors have studied how the gut microbiome can affect many health conditions, including lupus.

Researchers in China wanted to see if there was any connection between the health of a person’s gut and lupus. They decided to do a meta-analysis of lupus studies.¹

A meta-analysis is a way to compare research that has already been completed. It looks at multiple completed studies and compares results to see if there are any common trends. By combining the results of multiple studies, doctors and researchers can look at trends across many more people.

The researchers analyzed a group of 11 studies. These studies compared the microbiomes of about 400 people with lupus and about 1,300 people without lupus.¹

What is the gut microbiome?

The gut microbiome refers to the organisms that live in a person’s digestive tract. These microbes include bacteria, viruses, and fungi. They are often classified as "good" and "bad." But the balance of organisms that are considered good and bad is still being researched. The balance that is right for 1 person may not be right for someone else.^2,3

Every person’s microbiome is different. And the balance of good and bad organisms that make up the microbiome can change. Many things can affect and be affected by the gut microbiome. These include:^2,3

• The drugs you take
• Your environment
• Your diet
• Conditions such as cancer, autism, and autoimmune diseases

Lupus and gut bacteria research

The studies that the meta-analysis looked at suggested that people who have lupus are less likely to have as many variations in the type of microbes in their gut microbiome. People with active lupus have an even less diverse microbiome than people in remission. Taking steroids or hydroxychloroquine to treat lupus also reduces gut microbiome diversity.¹

Researchers found a reduced number of Ruminococcaceae bacteria in people with lupus. These bacteria help to protect the gut. They may also stop the body from activating B-cells, which can cause inflammation.¹

Researchers also found an increased number of Enterobacteriaceae bacteria in people with lupus. These bacteria can be responsible for lung and abdominal infections. They can also activate T-cells. T-cells are a part of the immune system that can have a negative effect on lupus.¹

What does this mean for lupus research?

These findings are all very interesting and may have important effects on future lupus research. For example, doctors and researchers may want to:¹

• Explore the gut microbiome and how it affects lupus symptoms
• Try to figure out if the microbiome could be the cause of lupus in some cases
• See if research on the microbiome could lead to treatments for lupus
• Explore how people with lupus can keep their gut microbiomes healthy while taking drugs to treat their lupus
• See if adding microbes to the gut can help reduce lupus symptoms

There is something important to remember when you read about new research like this. Scientists and statisticians often say, "correlation does not equal causation." That is, just because there is a link between lupus and changes in gut bacteria, there is no proof that 1 causes the other. Doctors do not know at this point whether:

• Changes in gut bacteria are caused by lupus
• Lupus is caused by changes in gut bacteria
• Lupus and changes in gut bacteria are unrelated and both caused by something else

Meta-analyses like these and the trends they show require more study. But they do help doctors make decisions on the next steps in research. The resulting research can lead to breakthroughs in both prevention and treatment.