Rheumatoid arthritis and autoimmune diseases: What is their relationship with our gut microbiome? Why are they on the rise?

Autoimmune diseases are a modern health problem for which scientists know little about their causes. But now there are very reasonable suspicions that the role of the intestinal microbiome is crucial!

Rheumatoid arthritis is an autoimmune disease that afflicts many people and prevents them from having a good quality of life. Scientists are now looking for its causes in the intestinal microbiome and in specific bacteria that "live" in it. Although they do not know exactly what "triggers" rheumatoid arthritis, a disease that actually attacks the joints with persistent inflammation, research is increasingly turning to a "culprit": the bacteria that live in our gastrointestinal tract.

Several studies have discovered very interesting connections between the intestinal microbiome, rheumatoid arthritis, and other diseases, in which the immune system "goes crazy" and attacks its own tissues.

A study published in 2013 by Jose Scher, rheumatologist, and director of the Center for Rheumatology and Immunology at New York University, found that people with rheumatoid arthritis were more likely to have a bacterium called Prevotella copri in their gastrointestinal tract, which there weren’t in the gastrointestinal tract of people without the disease. Two years later, in 2015, the same doctor published a study that found that patients with psoriatic arthritis, a similar autoimmune disease that affects the joints, had lower levels of other types of intestinal bacteria.

These two studies are part of a major scientific effort by researchers around the world to understand how the gut microbiome (the microbes that live in our gastrointestinal tract) affects our overall health. As we all know, the intestinal microbiome contains thousands of different species of bacteria with trillions of cells, more than we have in the rest of our bodies. In recent years, scientists have gathered a very large amount of evidence that these bacteria affect our health, and in fact, some trigger chronic diseases while others protect us from them.

"It is becoming increasingly clear that these microorganisms can affect our immune system even for non-gastrointestinal diseases," says Veena Taneja, an immunologist at the Mayo Clinic in Minnesota, USA. Taneja revealed clear differences in bacterial populations in mice genetically predisposed to rheumatoid arthritis. Among those most susceptible to the disease, their gut microbiome was dominated by a species of bacteria from the Clostridium family while in healthy individuals these bacteria were rare.

Why are autoimmune diseases on the rise?

Scientists find it challenging how these bacteria affect our immune system. In recent decades there has been an increase in autoimmune diseases. Many researchers of the intestinal microbiome claim that at least part of this increase is due to changes in the bacterial ecosystem of our gastrointestinal tract. Changes in diet, increased use of antibiotics and reduced contact with the natural world of plants and animals (which are full of beneficial microorganisms) have helped to change the bacteria that "live" in our bodies. "Our microbiome has changed significantly over the last century and especially over the last 50 years," said New York University microbiologist Martin Blaser, who blames these consequences on the reckless use of antibiotics. "Every generation loses precious bacteria that disappear."Such changes are evident that will have consequences." Blaser is a researcher specifically dealing with the well-known Helicobacter pylori. The sample was the bacteria of the microbiome from a group of children in the US and he found that H. pylori were present in only 6% of these children. He compared other studies that showed that this bacterium was common to the majority of people in many parts of the world, especially in developing countries. In the West, its gradual disappearance is probably due to antibiotics but also due to the improvement of sterilization conditions. But this ... disappearance has medical consequences: in another study in 2012, Blaser suggests that the presence of this bacterium in children reduces the risk of asthma, and the already manifested asthma, according to the researcher, is one of the diseases that show a steady increase in the last 3 decades in the US due to change in the intestinal microbiome.

Scientists like Blaser claim that bacteria in our gut microbiome have the power to determine how our bodies react to external invaders. A microbiome in dysbiosis, i.e. containing the wrong bacteria or the wrong proportion of bacteria, can affect our immune system so that it attacks not only external enemies but also our own body. The immune cells in our gastrointestinal tract, therefore, seem to have the ability to activate the cells that cause inflammation in the body, including the joints. However, although many scientists are optimistic that there is a clear link between the intestinal microbiome and rheumatoid arthritis, they have not clarified exactly what role bacteria play in triggering the disease. Scher claims that Prevotella copri stimulates an immune response that strikes arthritic tissue, or it may kill the beneficial bacteria that prevent immune cells from being so aggressive.

The treatment is located in the intestinal microbiome

Scher is optimistic that we will eventually be able to cure rheumatoid arthritis by modifying the intestinal microbiome. Dozens of researchers, including Scher and Blaser, are looking at possible strategies for using bacteria as drugs for autoimmune diseases. Millions of Americans are already consuming probiotics, which in theory contain beneficial bacteria that are said to cure diseases like acne and insomnia. Scher, like other researchers, is skeptical of such practices: "There is this ... notion that you can simply replenish the beneficial bacteria with probiotics. I do not think it is that simple. "Firstly it is not clear whether these probiotic bacteria survive from the digestive process." He believes that the change in the microbiome is through diet and has noticed that some patients with rheumatoid arthritis have benefited by eliminating the meat or adopting the Mediterranean diet (fish, olive oil, vegetables, and lean meat), although it is not clear why this happened.

Other scientists, such as Taneja at the Mayo Clinic, focus on specific bacteria instead of the diet. Taneja has even discovered that a species of the bacterium Prevotella prevents or inhibits rheumatoid arthritis and multiple sclerosis in mice and intends to start testing it on humans as well.

Another group of scientists, again, focuses on the chemical compounds that bacteria produce and are beneficial to autoimmunities, such as B. fragilis, for example, which secretes a molecule, polysaccharide A or PSA. Dennis Kasper, a microbiologist at Harvard University, who discovered the compound, also found that when PSA was given to mice, it protected against certain autoimmune diseases, such as multiple sclerosis. Kasper argues that PSA may be a more effective and reliable method of modifying the bacteria of the intestinal microbiome.

It already has an advantage over the drugs currently used in autoimmune diseases. And the reason is obvious, as Kasper explains: instead of suppressing the entire immune system - which does not benefit the patient - PSA leads the immune cells to continue to function normally without attacking the body’s cells.

We are living in a time when doctors do not use bacteria or metabolites in patients with rheumatoid arthritis, but scientists are optimistic that in 10 to 15 years the intestinal microbiome will be the key to the therapeutic approach to such diseases.

Learn about your gut microbiome today!

It is very simple and you can achieve it with an advanced test that will solve all your questions! It is called EnteroScan®, it is performed at Diagnostiki Athinon and is a group of specialized laboratory tests that analyze the Intestinal Microbiome and its functions. Along with other innovative and conventional laboratory tests, they shed light on a number of diseases and pathological conditions and mainly record how your gut functions and the state of your intestinal microbiome. So you can learn how to improve your health in natural ways, how to prevent the occurrence of diseases related to the modern way of life and of course, you can give answers to chronic diseases that afflict you! The examination is painless since it is done in a stool sample, which you can send even by courier!