Is the Human Microbiome Altered in Patients With Axial Spondyloarthritis?

At least 50 subjects, male and female, aged 18 or older, will be recruited to the study and assigned to one of five groups:

1. Ten TNF blocker-naïve ankylosing spondylitis patients
2. Ten TNF blocker-exposed ankylosing spondylitis patients
3. Ten TNF blocker-naïve nrSpA patietns
4. Ten TNF blocker-exposed nrSpA patients
5. Ten healthy age, diet and BMI-matched controls Inclusion and exclusion criteria will vary by study group. It is anticipated that the TNF-blocker naïve groups will be the most difficult to recruit, so these groups will serve as the baseline for age and diet matching for the other two groups. Up to seventy (70) additional TNF-treated axial SpA and healthy subjects may be asked to complete the dietary questionnaire, but will not provide stool samples unless age, diet and BMI-matched with a TNF-blocker-naïve axial SpA subject.

Inclusion Criteria:

• Able to provide informed consent
• Male or Female patients ≥18 years of age
• Additional Inclusion Criteria based on cohort

Exclusion Criteria:

• Current use of any pain-relieving medications other than NSAIDs, APAP and/or opioids
• Corticosteroid therapy or probiotic exposure within the last two weeks
• Antibiotic exposure within the past two months
• History of psoriasis or inflammatory bowel disease or reactive arthritis or any other chronic rheumatologic disease
• Active infection
• History of hepatitis B or C or HIV
• Active cancer or history of colon cancer or any form of chemotherapy or radiation within the past year
• Celiac disease
• Use of proton pump inhibitors within the prior two months
• History of clostridium difficile
• Pregnancy
• Active diarrhea (defined as a decrease in fecal consistency lasting four or more weeks)
• Additional Exclusion Criteria based on cohort