Can Intestinal Bacteria Cause Rheumatoid Arthritis?

Can Intestinal Bacteria Cause Rheumatoid Arthritis?

Researchers worldwide are exploring the flawed immune response that kindles inflammatory disease. Intestinal bacteria may hold the key to understanding what triggers rheumatoid arthritis inflammation. Inflammation defends the body against infection, but must turn on at just the right moment to repel an assault—and then quickly switch off when the invading pathogen is removed. Why does smoldering low-grade inflammation suddenly erupt into a raging autoimmune disease that attacks the joints and sparks the warmth, swelling and pain of rheumatoid arthritis (RA)?

One answer may lie in the microbiome—about 100 trillion intestinal bacteria microbes weighing up to three pounds—that normally live in the gut. “The microbiome shapes our immune system and can play an important role in autoimmune diseases,” says Assistant Professor of Medicine Shahla Abdollahi-Roodsaz, PhD, of New York University School of Medicine. “The microbiome in the gut activates immune cells that may travel throughout the entire body, including to the joints.”

For 2015-16, Dr. Abdollahi-Roodsaz was awarded funding as The Sontag Foundation Fellow of the Arthritis National Research Foundation (ANRF). An honor awarded by ANRF’s partner organization, The Sontag Foundation, that’s given towards the research project that they feel demonstrates the the most promise towards finding a cure for RA.

In 2013, New York University rheumatologists discovered that patients with RA are far more likely to have certain intestinal bacteria called Prevotella copri in their intestinal tracts than those without the disease. Evidence suggests that people recently diagnosed with RA may have teeming colonies of these intestinal bacteria, compared to healthy individuals.

With ANRF funding, Dr. Abdollahi-Roodsaz is investigating the immune response to the intestinal bacteria associated with the disease in a mouse model. The discovery of the link between the microbiome and RA has sparked revolutionary theories about the inflammatory role of the gut bacteria in autoimmune diseases such as RA. Some gut bacteria signal the immune system to mount a forceful inflammatory response, while other species may protect against inflammation. Does P. copri signal the immune system to respond so aggressively that it destroys joint tissue? Or does the overgrowth of P. copri displace more beneficial bacteria? How exactly these microbes trigger autoimmune diseases remains elusive—“and is what we are trying to understand.”

Animal studies reveal that mice, even when genetically modified to develop arthritis, don’t fall victim to the disease when raised in a germ-free environment. “What’s true for mice may also be true for humans,” she says. “Perhaps we can treat patients by specifically eliminating the harmful bacteria while preserving or even promoting the ‘good bugs.’”

In addition, Dr. Abdollahi-Roodsaz is investigating the role of specific molecules on immune cells responding to intestinal microbes. The focus of her research is a class of proteins called “Toll-like receptors” that form a line of defense against invading pathogens, but also react to certain intestinal bacteria. Intriguingly, the inflammatory response that spurs autoimmune diseases like RA suggests that the immune system overreacts to certain signals from bacteria.

Inflammation unleashes a flood of pro-inflammatory proteins called “cytokines” that trigger the immune system to attack the joints, causing debilitating pain, stiffness, and deformity. “We are investigating both genetic factors and the inflammatory proteins that exacerbate RA in relationship with the gut microbiome,” she says. “Several biologic drugs that target a specific cytokine, IL-17, are already in clinical trials, and IL-17 is a cytokine whose production can be strongly triggered by the gut bacteria.”

Disease-modifying drugs and biologic agents often slow the progression of RA, but the mechanisms that drive gut inflammation and joint damage remain a mystery. “With ANRF funding, we are doing basic research that could someday lead to novel treatments for the disease,” says Dr. Abdollahi-Roodsaz. “Despite current therapies, a cure for RA remains an enormous challenge.”

What intrigues you most about Dr. Abdollahi-Roodaz’s rheumatoid arthritis research? Leave a comment below.

Article Author
Arthritis National Research Foundation

The Arthritis National Research Foundation's mission is to provide initial research funding to brilliant, investigative scientists with new ideas to cure arthritis and related autoimmune diseases. Writing articles about the patients affected and the science being done to find a cure shows why we need to come together to #CureArthritis!

  • vickie morgan
    Posted at 15:13h, 14 August Reply

    That is exactly how mine was triggered. I absolutely know this! Stress poor diet and bacterial infection. Please get physicians to realize immune suppressants is a bandage and short time fix. Lifestyle and diet get the root cause. People are needing you to help them so don’t be so narrowed with just medicine its a disservice! If they care get an open mind. Could be their mother, daughter, wife, husband, son.. maybe that will open the mind and stop the rubber stamp medicine approach.

  • Tina
    Posted at 16:48h, 27 September Reply

    I agree. I also grew up with a poor diet and stress and then whamo! I was 14. RA seems to run in our family, my mother has it. I don’t think she had a very good diet either.

  • Sandra
    Posted at 04:01h, 01 October Reply

    It is truly exciting and comforting to see research for auto immune diseases being focused on the health of gut flora – since I believe most of our immune cells live there, this makes such sense. It is when this bad bacteria gets through the gut wall due to ‘leaky gut syndrome’ i.e. intestinal permeability and into the blood stream that something called ‘molecular minicry’ occurs, the immune cells attack what should not be in the blood stream but contained safely inside the intestine. Many conditions cause this intestinal problem. Like Vicky above I feel I know how my RA came about – I abused codeine in my late teens and 20s which caused me digestive problems all my life and which finally tripped over into an auto immune problem in my late 50’s. Other reasons can be over use of antibiotics, immune system development disruption as an infant or so many other cascading symptomatologies. Modern medicine indeed tries to put out the fire of inflammation with some pretty devastating medications rather than going to the root cause as Dr Abdollahi-Roodaz is working on. Hope for the future! However I don’t think the drug companies will be very happy with the answer being dietary and lifestyle choice though.

  • Sandra
    Posted at 16:28h, 27 December Reply

    I think the gut bacteria is laying a huge roll in causing RA. I just recently was diagnosed with RA and have been suffering with digestive issues for nearly a year. Lost lots of weight. Nutritionally imbalanced. Prednisone doesn’t seem to help making condition worse. Lots of pain in joints and colon. Not sure if I can be helped.

  • Martin Farmer
    Posted at 00:28h, 12 February Reply

    An absolutely spot on article . To cut a long story short, have had food intolerances for twenty years following a sloppy diet and unnecessary courses of antibiotics Have now contracted rhumatoid arthritis which appears to be no coincidence.Now improving after taking medication and following an anti inflammatory diet. Pleased to see you examining the root of the problem.

  • Elizabeth
    Posted at 13:02h, 25 March Reply

    I was diagnosed with RA two years ago. I have always eaten a healthy diet. Never taken antibiotics. Everyone has stress but I’ve had no more than the average person. I’m now eating a totally in inflammatory diet. This is a good study but isn’t the whole picture.

  • Annette Adams
    Posted at 17:50h, 26 May Reply

    I firmly believe there is a connection between our microbiota and Rheumatoid Arthritis. In May 2004 I took a combination of antibiotics called Heliclear. My health has never recovered. Within 3 months of taking the Hel iClear the diagnosis was Chronic Fatigue Syndrome. Within 6 months the diagnosis became Fybromialgia. By January 2005 my GP added Osteoarthritis, but I believe he got it wrong. It took until May 2006 to get to see a Rheumatologist who confirmed Rheumatoid Arthritis. By the end of 2009 both hips and both knees had been replaced and I was considered to need both shoulders and both elbows replacing also.

    In the Summer of 2016 I started reading extensively about our gut flora (Microtiota). So far my efforts to attempt to improve the balance of intestinal flora through diet have met with limited success. The combination of the biological drug infusions needed to control the Rheumatoid Arthritis and the numerous bacterial and viral infections caused by having my immune system surpressed appear to hamper my best attempts at self-help through diet.

    The proposed solution to my current combination of bacterial infections, is to stop my biological drug infusions and administer antibiotics. To me this just sounds like repeating the process tried in 2004 and making the underlying problem worse instead of better.

    Any alternative suggestions anyone?

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