Is the Human Microbiome Altered in Patients With Axial Spondyloarthritis?

This study aims to compare biological communities in stool samples obtained from age, diet and BMI-matched subjects in five study groups: subjects with ankylosing spondylitis (AS) never treated with tumor necrosing factor (TNF) inhibitors, subjects with ankylosing spondylitis previously or currently treated with TNF inhibitors, subjects with non-radiographic axial spondyloarthritis (nrSpA) never treated with tumor necrosing factor (TNF) inhibitors, subjects with non-radiographic axial spondyloarthritis previously or currently treated with TNF inhibitors and healthy participants. The differences in fecal microbiota composition will be explored using shotgun metagenomic sequencing through the University of Washington. The investigators predict that this study will confirm a significant difference between the fecal microbiota composition (FMC) of both AS and nrSpA patients and controls.