Table 3.
Summarizes the evaluations of beta diversity in the included research.
| Study | β diversity | Findings | Statistic value |
|---|---|---|---|
| Huang (2024) | PCoA based on Bray–Curtis dissimilarity | A significant difference in oral microbial composition among S and H | p < 0.01 |
| PCoA based on the Unweighted UniFrac distances | A significant difference in oral microbial composition among S and H | p < 0.01 | |
| PCoA based on the Weighted Unifrac distance | A significant difference in oral microbial composition among S and H | p < 0.01 | |
| Yang (2022) | PCoA based on Bray–Curtis dissimilarity | A significant difference in oral microbial composition among S and H | p = 0.005 |
| Zhao et al. (2025) | PCoA based on Bray–Curtis dissimilarity | A significant difference in oral microbial composition among S and H | p = 0.002 |
| Yao et al. (2025) | PCoA based on Bray–Curtis dissimilarity | A significant difference in oral microbial composition among S and H | p = 0.001 |
| Sun et al. (2023) | PCoA based on the Unweighted UniFrac distances | A significant difference in oral microbial composition among S and H | p < 0.001 |
| Manzoor et al. (2025) | PCoA based on Bray–Curtis dissimilarity | A significant difference in oral microbial composition among S and H | p = 0.003 |
| PCoA analysis based on Jaccard distance | A significant difference in oral microbial composition among S and H | p = 0.007 | |
| He et al. (2024) | PCoA based on Bray–Curtis dissimilarity | A significant difference in oral microbial composition among S and H | p = 0.003 |
| Manzoor et al. (2024) | PCoA based on Bray–Curtis dissimilarity | No difference in oral microbial composition among S and H | p = 0.325 |
| PCoA based on Jaccard distance | No difference in oral microbial composition among S and H | p = 0.850 | |
| PCoA based on the Weighted Unifrac distance | No difference in oral microbial composition among S and H | p = 0.403 | |
| Zheng et al. (2026) | PCoA based on Bray–Curtis dissimilarity | A significant difference in oral microbial composition among S and H | p = 0.001 |