Table 5.

Differences in the relative abundance of bacteria at phylum level.

Studies	Main alternations of CP
Soffritti et al., 2021	Bacteroidetes↑, Firmicutes↑, Proteobacteria↓, Actinobacteria↓.
Shi et al., 2022	Firmicutes↑, Fusobacteria↑, Actinobacteria↑,Proteobacteria↓.
Schult et al., 2022	Firmicutes↑,Proteobacteria↑.
Ren et al., 2021	Firmicutes↑, Fusobacteria↑, Bacteroidetes↓, Proteobacteria↓.
Rafiqul Islam et al., 2022	Firmicutes↑, Proteobacteria↓.
Gupta et al., 2022	Firmicutes↑,Proteobacteria↓,Fusobacteriota↓,Campilo-bacteriota↓, Synergistota↓, Spirochaeota↓, Patescibacteria↓, Desulfobacter↓.
Cui et al., 2022	Fusobacteriota↑, Bacteroidetes↓, Actinobacteriota↓.

Four studies have not mentioned the information about differences in the relative abundance of bacteria at phylum level. (Iebba et al., 2021; Miller et al., 2021; Wu et al., 2021; Callahan et al., 2022),

The symbols "↑" and "↓" respectively represent the increase and decrease in the relative abundance of bacteria at the phylum level.