One or more types of bacteria may trigger the onset of rheumatoid arthritis in some people. No bacteria causes all cases of rheumatoid arthritis. One or more bacterial infections may induce symptoms in susceptible people, and without resolution, can lead to development of RA.
As an example, a colleague, who I’ll call Karen (not her real name), asked me about what could have caused her RA. When I mentioned that some patients (20%)  have infections within 6 months of onset, she remarked that she had had inflamed gums and problems with her teeth for years because she had avoided a dentist. I suggested that those infections may play a role in getting RA. She went to the dentist.
Since no one wants to be given gum disease and tooth problems that fester for years to see if RA develops, the role of bacteria causing gum disease is hard to prove definitively.
As a precaution, I recommend that everyone tries to maintain healthy gums and teeth. If you’re having issues with gum disease, please consider consulting with a dentist to prevent long-term gum disease and tooth problems..
Periodontal disease is significantly more common in RA patients than osteoarthritis patients .
RA patients with gum disease have more swollen joints, greater disease activity, and more narrow spaces in the affected joints (joint damage detected by x-rays) . RA patients with gum disease also have higher titers of autoantibodies associated with RA, namely RF and anti-CCP antibodies .
Porphyromonas gingivalis is a common disease-causing bacteria found in gum disease or gingivitis. Antibodies specific for this bacteria are found in many RA patients .
Aggregatibacter actinomycetemcomitans grows in the human mouth and can cause local aggressive periodontitis—rapid bone destruction and tooth attachment. Infection with this bacteria can alter neutrophil function which may be a risk factor for RA development .
Both of these bacteria alter host proteins by adding citrulline groups. Some RA patients develop antibodies (anti-CCP) to these proteins. Several groups propose that infection with Porphyromonas gingivalis  or Aggregatibacter actinomycetemcomitans  may play a role in altering the immune response to some human proteins and can eventually lead to the autoimmune disease.
If your gums bleed while brushing or flossing, it is likely that the bacteria in your mouth and inflamed gums are getting into your bloodstream, too.
It would probably be worthwhile to check if you’re ingesting sufficient zinc, selenium and other trace minerals to help maintain a balanced immune system. Adding a good sea salt to your diet may improve the taste of your food and increase your trace minerals.
Staphyloccocus aureus is the most common bacteria to cause joint infections, especially in artificial joints. It is a gram positive, round bacteria. They usually grow in grape-like clusters. Staphyloccocus aureus is abbreviated as S. aureus, or sometimes Staph aureus. It can also be misspelled as a staff infection.
S. aureus is found in the nose in about 20% of people. It is also found on the skin.
Unfortunately, many S. aureus infections are resistant to a variety of antibiotics.
One group of antibiotic resistant S. aureus are called MRSA for methicillin resistant Staphyloccocus aureus. Hospitals are a main source of antibiotic resistant bacterial infections or nosocomial infections. Recently, infection with MRSA was also found in the general population, more often in nursing homes.
Some of these strains can successfully be treated with vancomycin although vancomycin resistant strains are now being detected.
Mycoplasma arthritidis, Mycoplasma fermentans, Mycoplasma pneumoniae, M. hominis; and M. salivarium have been found in the synovial joints of some RA patients  and have stimulated immune responses . However, other scientists have not detected significant differences between anti-Mycoplasma antibody titers in joint fluid and serum .
It’s feasible that Mycoplasma may induce or flare rheumatoid arthritis in some patients but not all. Other studies suggest that the immune response of RA patients is less effective against Mycoplasma sp. antigens than healthy people. . However, treatment strategy needs further refinement .
Lyme disease which is caused by an infection with Borrelia burgdorferi can induce a reactive arthritis. The symptoms are distinct from rheumatoid arthritis.
If bacterial infections are triggering or causing flares with your rheumatoid arthritis, will treatment with antibiotics help?
Some physicians and rheumatologists have prescribed long term antibiotic treatment, minocycline, for RA and have obtained success in many patients. Other rheumatologists still consider it preliminary.
Scientific studies indicate that up to 30% of RA patients benefit from low dose, long term antibiotic therapy using minocycline [25-28].
As a boost to overall health, eat a diet rich in colorful vegetables and fruits, some meat from animals raised on pasture or wild caught Alaskan Salmon.
Secondly, try using a probiotics capsule (friendly bacteria) to coat your mouth. I open a capsule of probiotics, dilute with water (does not dissolve), and swish the mixture around the inside of the mouth.
For anyone, especially those on immunosuppressive therapy, please consult with your healthcare provider to discuss the risks and potential benefits from probiotics for your individual situation.
Antibiotic treatment will not get rid of any viruses, parasites, nor molds.
References available by request.