Fig. 2

Bacterial diversity in alveolar lavage fluid samples of children in groups A1, A2, and B. A The number of observed species. B α diversity shown by Simpson's Diversity Index. C β diversity expressed as the Bray–Curtis distance in the alveolar lavage fluid samples. D NMDS based on the Bray–Curtis distances at the OTU level which met the 97% identity threshold. E UPGMA clustering of the microbiome classification maps in the three groups using the UniFrac distance showed relatively clear separation between groups