Characterisation of Intestinal Microbiota of Patients With Spondyloarthritis or Rheumatoid Arthritis

Inclusion Criteria: Patients: * Patient ⩾ 18 years; * Diagnosed as spondyloarthritis (SpA) according ASAS classification, or rheumatoid polyarthritis according ACR/EULAR; * Affiliated to a social security scheme; * Have signed the written informed consent form. Healthy control subjects: * Adult women and men; * Subjet free of chronic pathology; * Affiliated to a social security scheme; * Have signed the written informed consent form. Exclusion Criteria: Patients: * Patients unable to understand the proposed study and/or sign a informed consent form; * Pregnant women or breast feeding women; * Patient ⩾ 18 years; * Patients under guardianship or curatorship; * Have taken antibiotic 1 month prior to inclusion or digestive coloscopy 6 months prior inclusion; * Presenting acute or chronic severe pathology may likely to interfere with the interpret of outcome; * Foreign patients under french AME scheme; * Patients had have participated in the prior study Microbiart. Healthy control subjects: * Subjects unable to understand the proposed study and/or sign a informed consent form; * Pregnant women or breast feeding women; * Subjects \< 18 years; * Subjects under guardianship or curatorship; * Presenting acute or chronic severe pathology may likely to interfere with the interpret of outcome; * Refusal of subjects to participate to the study; * Foreign patients under french AME scheme; * Subjects had have participated in the prior study Microbiart.