As secondary objectives, the study aims:~to research the abundance of bacterial strain of R. gnavus in mucosal sampling by biopsy;~to study the interaction between R. gnavus bacterium and mucus from histological sampling;~to correlate the expression of genes of intestinal mucus with the variations of identified microbiota of mucus biopsy;~to study the interaction between bacteria and intestinal epithelial cells during culture;~to demonstrate perturbations of the immune responses by dysbiosis.
The primary objective of this case-control study aims to explore the role of bacterium Ruminococcus gnavus (R. gnavus) with intestinal biopsy and faecal sampling in the initiation and the development of spondyloarthritis (SPA) in comparison with health control subjets (patients without chronic disease but have indication to digestive endoscopy).