Evolution of Intestinal Microbiota in Patients With Juvenile Spondylarthropathy According to Typology of Treatment

Stool samples will be taken from each patient to look for changes in intestinal microbiota. These collections will be made on Day 0 +24h, 24 hours before the 1st follow-up visit after 1 month of treatment with non-steroidal anti-inflammatory drugs, 24 hours after the second follow-up visit (between months 3 and 4) and finally, at the end of treatment.

7 ml of blood will be taken from each patient before treatment i.e. at the inclusion visit and at the end of treatment.