Fig. 3: P. copri mitigates H9N2 infection by regulating intestinal microbiota.

a Establishment of gut microbiota depletion model; n = 6/group. b Survival rates of mice across different groups post-H9N2 infection. c Body weight loss percentage in different groups following H9N2 infection. d Comparative analysis of OTU numbers among groups; n = 6/group. e PCoA and NMDS analysis based on weighted UniFrac distances to identify microbial structural changes. f Comparative analysis of Simpson, Pielou, Shannon, and observed features indexes. g Relative abundance analysis at phylum level. h Relative abundance analysis at genus level. i Simper analysis shows the top 20 species with the highest contribution to differences between H9N2 and PRE + H9N2 groups and their abundance. j LEfSe analysis; LDA score > 3. k Bacterial phylogenetic branches, with different circle layers from inner to outer representing seven taxonomic levels: domain, phylum, class, order, family, genus, and species; each node represents a species classification at that level. l Correlation analysis between dominant bacterial genera and infection-related parameters, calculated using Pearson correlation coefficient. Six samples in each group were used for 16S rRNA analysis. Samples for d-l were collected on day 6 after H9N2 infection. The data in panels b, c are representative of three independent experiments, yielding an identical pattern of results. Results are shown as means ± SD, with statistical significance determined by one-way ANOVA for four groups. *P < 0.05; **P < 0.01; ***P < 0.001.