Fig. 1

Dysbiosis index distributions among axSpA patients and controls. A Distributions of dysbiosis index (DI) score 1–5 among axSpA patients (nr-axSpA and AS combined) and controls. Unadjusted between-group difference in DI score 1–5: 0.45 (95% CI 0.16 to 0.74), p=0.003. Adjusted (for age, sex, BMI, and smoking) between-group difference in DI score 1–5: 0.34 (0.04 to 0.64), p=0.028. B Distributions of DI score 1–5 among nr-axSpA patients, AS patients, and controls. Nr-axSpA versus controls: unadjusted between-group difference in DI score 1–5: 0.25 (−0.09 to 0.60), p=0.154; adjusted (as above): 0.17 (−0.19 to 0.54), p=0.409. AS versus controls: unadjusted: 0.55 (0.22 to 0.88), p<0.001; adjusted: 0.43 (0.07 to 0.78), p=0.019. AS versus nr-axSpA: unadjusted: 0.30 (−0.06 to 0.64), p=0.098; adjusted: 0.20 (−0.18 to 0.56), p=0.286. Number of subjects per group presented at the bottom of (or above) the bars. AS ankylosing spondylitis, axSpA axial spondyloarthritis, BMI body mass index, CI confidence interval, DI dysbiosis index, nr-axSpA non-radiographic axial spondyloarthritis