Table 3.
Characteristics of the included studies.
| Studies | Year | Country | Type of study | Study population | Oral microbiota analysis technique | Samples | ||
|---|---|---|---|---|---|---|---|---|
| Wu et al., 2021 | 2021 | China | Case-control | CP (140), HC (44) | 16S rRNA gene sequencing | Throat swab samples | ||
| Soffritti et al., 2021 | 2021 | Italy | Cross-sectional | CP (39), HC (36) | Whole-genome sequencing | Oral rinse samples | ||
| Shi et al., 2022 | 2022 | China | Case-control | CP (10), HC (10) | 16S rRNA gene sequencing | Throat swabs | ||
| Schult et al., 2022 | 2022 | Germany | Case-control | CP (108), HC (26) | 16S rRNA gene sequencing | Saliva samples | ||
| Ren et al., 2021 | 2021 | China | Case-control | CP (48), HC (100) | 16S rRNA gene sequencing | Tongue coating samples | ||
| Miller et al., 2021 | 2021 | USA | Case-control | CP (53), HC (59) | 16S rRNA gene sequencing | Saliva samples | ||
| Rafiqul Islam et al., 2022 | 2022 | Bangladesh | Cross-sectional | CP (22), HC (19) | Whole-genome sequencing | Saliva samples | ||
| Iebba et al., 2021 | 2021 | Italy | Case-control | CP (26), HC (15) | 16S rRNA gene sequencing | Tongue coating samples | ||
| Gupta et al., 2022 | 2022 | India | Case-control | CP (30), HC (24) | 16S rRNA gene sequencing | Saliva samples | ||
| Cui et al., 2022 | 2022 | China | Cohort | CP (38), HC (150) | 16S rRNA gene sequencing | Tongue coating samples | ||
| Callahan et al., 2022 | 2022 | USA | Case-control | CP (16), HC (90) | 16S rRNA gene sequencing | Saliva samples | ||