Table 2.
The main characteristics of the included studies
| First Author | year | Type of study | Type of disease | No. of subjects | No. of healthy controls | RT dose (Gy) | Analysis technique microbiome | sample | Evaluation criteria of diarrhea | No of patients reporting diarrhoea | Before–after design | CCRT* or not | No. of testing time point | testing time point |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mitra | 2020 | Prospective cohort | Cervical cancer | 35 | 0 | – | 16 s-rRNA | Stool | EPIC | – | Yes | Yes | 4 | Before RT |
| Wang | 2019 | Prospective cohort | Cervical cancer | 18 | 0 | 50.4 Gy | 16 s-rRNA | Stool | – | 10 | No | No | 2 | One day before RT, |
| Reis Ferreira | 2019 | Prospective cohort | Prostate cancer | 32 | 6 | 60–74 Gy | 16 s-rRNA | Stool sigmoid /rectum mucosa | RTOG | – | Yes | – | 6 | Before RT, |
| Medrano | 2017 | Prospective cohort | Cervical cancer | 20 | 20 | – | 16 s-rRNA | Rectum | EPIC | – | Yes | – | 4 | Before RT, |
| Wang | 2015 | Retrospective study | Cervical cancer; anal canal cancer and rectal cancer | 11 | 4 | 44-50 Gy | 16 s-rRNA | Stool | CTCAE | 5 | Yes | No | 2 | Before RT, |
| Nam | 2013 | Prospective cohort | Cervical cancer and endometrial cancer | 9 | 6 | 50.4 Gy | 16 s-rRNA | Stool | Diarrhea Indices | – | Yes | – | 4 | Before RT, |
| Manichanh | 2008 | Prospective cohort | Cervical cancer, endometrial cancer and rectal cancer | 10 | 5 | 43.2–54 Gy | 16 s-rRNA | Stool | CTCAE | 6 | Yes | – | 4 | Before RT, |
| Cuzzolin | 1992 | Prospective cohort | Gynecologic cancer | 15 | 15 | 40 Gy | Bacterial culture and counting | Stool | – | – | Yes | No | 5 | Before RT, |
EPIC The Expanded Prostate Cancer Index Composite questionnaire, CTCAE common terminology criteria for adverse events, RT radiotherapy, CCRT concurrent chemoradiotherapy, RT radiation therapy
– Not mentioned in the text