5. Conclusion
We described the efficacy of probiotics for the prevention or treatment of viral-based infectious diseases; more than 20 strains improved the anti-inflammatory interleukins and anti-body production against viruses. Moreover, virus titres were lowered after probiotics supplementation periods. The large number of viral species and their subtypes as well as the high mutation rate of viruses do not allow scientists to discover appropriate vaccines and antiviral drugs, so, the administration of pro/prebiotics - as immune function modulators and antibiotic-related side effects removers – is recommended. Although further detailed research is necessary, the authors recommend researchers/physicians/dietitians to use probiotics as more rational adjunctive option in COVID-19 pandemic, especially in mechanically ventilated patients.