Fig. 4

Linear discriminant analysis (LDA) score histogram for differential OTUs of nasal secretions (A) and oral mucosa (B) between OS and control. LDA scores were calculated among classes (Kruskal–Wallis test) and between subclasses (Wilcoxon’s test), and significant differences (P < 0.05) were produced. Differential taxa were identified according to a statistical significance level of 0.05 and an LDA threshold score of > 3 (g: genus, f: family, o: order, c: class, p: phylum). EGNS: experimental group nasal secretions; CGNS: control group nasal secretions; EGOM: experimental group oral mucosa; CGOM: control group oral mucosa