Table 3.
Microbial diversity in each study
| No. | Study | Alpha diversity index | Alpha diversity | Beta diversity index | Beta diversity |
|---|---|---|---|---|---|
| 1 | Aarts et al. [12] | Shannon, Chao1 | No significant differences | – | – |
| 2 | Jiang et al. [9] | ACE, Chao1, Shannon, Simpson | No significant differences | Unweighted and weighted UniFrac, Bray–Curtis PCoA | Could not be differentiated |
| 3 | Prehn-Kristensen et al. [14] | Shannon, Chao1 | Decreased (pShannon = 0.036) | ANOSIM, ADONIS, Betadisper from the R package vegan v2.4–1 | Differed significantly (pANOSIM = 0.033; pADONIS = 0.006; pbetadisper = 0.002) |
| 4 | Wang et al. [10] | Shannon, Chao1 |
Shannon index (p = 0.0378) and Chao index (p = 0.0351) were increased significantly in ADHD Simpson index (p = 0.0339) was decreased significantly in ADHD |
Unweighted & weighted UniFrac, PCoA | No significant differences |
| 5 | Wan et al. [11] | Shannon, Chao1, Simpson | No significant differences | – | – |
| 6 | Szopinska-Tokov et al. [13] | Shannon–Wiener, Faith’s phylogenetic diversity | No significant differences | UniFrac distance metric, ADONIS, Betadisper ver 2.5–2, PCoA | Differed significantly (10 genera showed nominal difference) |