Statistical analyses were implemented at the R platform (https://www.r-project.org/). Permutational multivariate analysis of variance (PERMANOVA) was performed with the adonis function of the vegan package, and the adonis P-value was generated based on 1,000 permutations. The method of effect size analysis was referred as Wang et al. (2020) (link). The no-metric multidimensional scaling (NMDS) analysis was used as the ordination methods (metaMDS function in vegan package) for compositional data. The Procrustes coordinates analysis and significance were generated using the procuste and procuste.randtest functions in vegan package. The principal component analysis (PCA) was performed and visualized using the ade4 package. The Wilcoxon rank-sum test was used to measure statistical differences in diversity and taxonomic levels between two cohorts. P-values were corrected for multiple testing using the Benjamini–Hochberg procedure.