Fig. 3

a: Nonmetric multidimensional scaling (NMDS) ordination with Bray-Curtis distance of the upper respiratory tract (URT) and lower respiratory tract (LRT) in healthy horses (n = 6). b: Alpha diversity measures (Chao1 and Shannon) in both upper and lower respiratory tract samples. *** significant decrease in the richness of the local bacterial community in the lower respiratory tract (LRT) compared to the upper respiratory tract (URT) (p = 0.0043, Wilcoxon test) in healthy horses (n = 6)