Global Diversity
According to the bioinformatics pipeline, with 100% accuracy in the mock communities, bacterial taxa were identified correctly at the genus level. In total, 2677 ASVs were identified, of which Bacteroidota, Firmicutes, and Proteobacteria were the most abundant bacterial phyla, and Prevotella , Alloprevotella , and Veillonella were the most abundant bacterial genera in the whole study population (N=142) (Figures 3 and 4). In terms of α diversity (microbial diversity within samples), there were no differences in the number of observed unique ASV per sample (adjusted p-value= 0.476), Shannon index (adjusted p-value=0.559), or CHAO1 index (adjusted p-value=0.492). Regarding the β diversity (microbial diversity between samples), PERMANOVA models showed significant differences in both Bray-Curtis (adjusted p-value=0.018) and weighted UniFrac (adjusted p-value=0.039) distance measures.