Microbial EV composition at the genus level
Taxonomic profiling of the microbial EVs isolated from EBC samples was conducted as described above, which revealed that Acinetobacter ,Pseudomonas , Staphylococcus , Bacteroides , andSphingomonas were the most prominent genera in the EBC samples (Figure 2A ). Acinetobacter was the most common microbial EV genus in the control (13.0%) and asthmatic (5.4%) EBC samples, followed by Staphylococcus (5.2%) and Pseudomonas (5.0%) in the healthy control group and Sphingomonas (5.0%) andBacteroides (4.0%) in the asthma group. Comparison of the average relative abundance of the 25 most common microbial EV genera in the healthy control and asthma groups using a heat map demonstrated the differential abundance within each sample and between the groups (Figure 2B ). Furthermore, t-test analysis of the average relative abundance of microbial EV genera yielded multiple taxa that significantly differed between the control and asthma groups (Figure 2C ). The five most common genera that were enriched in the control group in descending order of proportion wereAcinetobacter , Staphylococcus , Bifidiobacterium ,Blautia , and Collinsella , while Sphingomonas ,Akkermansia , Methylophaga , Acidocella , andMarinobacter were the most common five genera that were significantly depleted in the healthy control group (p <0.05). The compositional variation between the microbial EV profiles of EBC samples obtained from patients with non-eosinophilic and eosinophilic asthma was also assessed, and no discernable difference was observed at the phylum and genus levels (Figures S2 and S3 ).