Fig 2. Comparison of beta diversity in upper respiratory mucosa microbiota between patients with RA and healthy controls.

Beta diversity was estimated and visualized on the top two PCoA axes based on the UniFrac distance (A: unweighted; B: weighted) and Bray-Curtis distance (C). Statistical differences in beta diversity between the two groups were determined using PERMANOVA. Abbreviations: RA, Rheumatoid arthritis; PCoA, Principal coordinate analysis; PERMANOVA, Permutational multivariate analysis of variance.