Role of Oral and Intestinal Microbiota in Rheumatoid Arthritis (RA)

If you would like to participate in this study, we will first ask you several questions
regarding the status of your arthritis, the medications you use or have used in the recent
past, your social and dietary habits, and your medical and surgical history. If your answers
tell us that you are the right patient for our study, we will go over a consent form which
describes in more detail how we will study your intestinal and mouth bacteria, the immune
cells in your blood and other genes, enzymes and proteins that tell us about your disease
status.

If you have Psoriatic Arthritis (PsA) or are healthy with no history of arthritis, and would
like to participate in this study, your participation would involve only one or two visits,
and no treatment.

If you have Rheumatoid Arthritis (RA), your participation would involve six visits, and you
would be randomly assigned to receive treatment with the antibiotic doxycycline, or the
antibiotic vancomycin, or no antibiotic treatment.

Inclusion Criteria:

- Rheumatoid Arthritis (RA) patients must meet ACR criteria for RA

- RA patients: duration of disease will be greater than 6 weeks and less than 2 years.

- RA patients should have a DAS28 (Disease Activity Score 28) greater than or equal to
5.

- PsA patients will be required to have disease duration and DAS28 similar to the RA
patients, and to meet Moll and Wright criteria for PsA.

- Allowable medications for both groups at study entry will include: prednisone (or
equivalent) 5 mg or less per day (stable dose for at least 2 months); methotrexate 15
mg or less per week (stable dose for at least 2 months); and NSAIDs at FDA-approved
doses.

- Healthy controls will be age- and sex-matched individuals with no personal or family
history of inflammatory arthritis.

Exclusion Criteria:

- Patients who are unable to provide informed consent.

- Pregnant or lactating women.

- Recent (<3 months prior) use of any antibiotic therapy

- Current consumption of probiotics

- Current extreme diet (parenteral nutrition, macrobiotic diet, etc.)

- Prednisone >5 mg/day or equivalent

- Use of other DMARDs with known antibiotic properties (Gold salts, hydroxychloroquine,
sulfasalazine or minocycline).

- Use of biologic DMARDs

- Known inflammatory bowel disease

- Known gastrointestinal (GI) tract neoplasm.

- Recent GI tract infection (gastroenteritis, colitis, diverticulitis, appendicitis)

- Chronic unexplained diarrhea.

- Any GI tract surgery leaving permanent residua (e.g., gastrectomy; bariatric surgery;
colectomy)

- Significant liver, renal or peptic ulcer disease, defined as:

- Liver: AST/ALT > 2 x upper limit of normal (ULN)

- Renal: Creatinine >1.5 or endstage renal disease

- Peptic ulcer disease: recent ulcer or GI bleed (within past 12 months)

- Inability or unwillingness to abstain from alcohol consumption.