Role of probiotics to combat viral infections with emphasis on COVID-19.

Interspecies transmissions of viruses between animals and humans may result in unpredictable pathogenic potential and new
transmissible diseases. This mechanism has recently been exemplified by the discovery of new pathogenic viruses, such as the
novel severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) pandemic, Middle-East respiratory syndromecoronavirus epidemic in Saudi Arabia, and the deadly outbreak of Ebola in West Africa. The. SARS-CoV-2 causes coronavirus
disease-19 (COVID-19), which is having a massive global impact in terms of economic disruption, and, above all, human health.
The disease is characterized by dry cough, fever, fatigue, myalgia, and dyspnea. Other symptoms include headache, sore throat,
rhinorrhea, and gastrointestinal disorders. Pneumonia appears to be the most common and severe manifestation of the infection.
Currently, there is no vaccine or specific drug for COVID-19. Further, the development of new antiviral requires a considerable
length of time and effort for drug design and validation. Therefore, repurposing the use of natural compounds can provide
alternatives and can support therapy against COVID-19. In this review, we comprehensively discuss the prophylactic and
supportive therapeutic role of probiotics for the management of COVID-19. In addition, the unique role of probiotics to modulate
the gut microbe and assert gut homeostasis and production of interferon as an antiviral mechanism is described. Further, the
regulatory role of probiotics on gut-lung axis and mucosal immune system for the potential antiviral mechanisms is reviewed and
discussed.