الفهرس 
Probiotics and COVID-19Only 14 pages are availabe for public view
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Abstract
The main function of the microbiota of different mucosal surfaces is in colonization resistance, i.e., the reduction in the probability of developing infections either by the direct action of microbiota upon microbes or indirectly (mainly by interactions with the host immune system). However, recently specific interactions and crosslinks between the gut microbiota and the lungs have been recognized, particularly with regard to respiratory immune and anti-microbial reactions. This is often known as the ‘gut-lung axis’ or ‘a common mucosal immunological system’.
Different studies have explored the use of probiotics to reduce the risk of respiratory infections, with a focus on viral upper respiratory tract infections (URTI) in particular (90% of URTIs are viral in nature) (3).
COVID-19 infection affects the lung tissues and gut, activating the inflammatory reaction. It raises the proinflammatory cytokines (IFN-γ, TNF-α) which leads to the cytokine storm. This response is due to the activation of T helper cells (Th1) cell response in the lung tissue (5). In the case of the human gut environment, dysbiosis in the gut microbiota results in the imbalance of Th1 and Th2 which leads to the activation of proinflammatory cytokine and the cytokine storm in the lungs as well. Administration and consumption of probiotics advance the immune system by boosting the level of type I interferons, antigen-presenting cells (APC), Natural Killer cells (NK cells), and B and T cells of the lungs (8). Probiotic supplementation can also improve the pro-and anti-inflammatory cytokines, leading to recovery by reducing the cell damage in the lungs.
Available studies and abstracts concerning Probiotics in the treatment and prevention of COVID-19 were identified.