Table 3. Components of the probiotics in each RCTs.
| Type of strains | Elmira Akbari (2016) | Omid Reza Tamtaji (2018) | Azadeh Agahi (2018) | Y. Kobayashi (2019) | Yun-Ha Hwang (2019) |
| Bifidobacterium bifidum | √ | √ | √ | ||
| Bifidobacterium breve A1 | √ | ||||
| Bifidobacterium lactis | √ | ||||
| Bifidobacterium longum | √ | √ | |||
| Lactobacillus acidophilus | √ | √ | √ | ||
| Lactobacillus casei | √ | ||||
| Lactobacillus fermentum | √ | √ | |||
| Lactobacillus plantarum | √ | √ |
Note: √ represents containing this type of strain in the component of probiotics.