Gut Microbiota Might Act as a Potential Therapeutic Pathway in COVID-19.

It has been very recently suggested that individuals with chronic gut inflammation are highly susceptible to COVID-19. They constitute the serious cases of COVID-19, in which inflammatory cytokine storm is observed. On the contrary, the healthy gut microbiota is linked with low chronic gut and systemic inflammation. This raises the idea that maintenance of the healthy gut microbiota and prevention of gut microbial dysbiosis in COVID-19 patients might avoid the increased cytokine storm, which in turn might reduce the mortality rate. It has been shown that the modulation of the gut microbiota is an effective strategy to strengthen immunity and might be a possible treatment for individuals with viral infections. Currently, there is no clinical data considering the impact of the modulation of the gut microbiota on the treatment of COVID-19. We hypothesize that targeting the gut microbiota might be a novel therapeutic approach or at least a supportive therapy. In the present review article, we described the interaction between SARS-CoV-2 and gut microbiota dysbiosis through two possible mechanisms, including aberrant immune activation and aberrant mammalian target of rapamycin (mTOR) activation. Further, the disruption of the gastrointestinal reninangiotensin system (GI RAS), dysregulation of the coagulation and fibrinolytic systems, and the activity of human serine proteases in COVID-19 pathogenesis were addressed. We also provided possible strategies to restore all the discussed aspects via gut microbiota modulation.

The predictive power of serum vitamin D for poor outcomes in COVID-19 patients.

Considering the high prevalence of vitamin D deficiency worldwide and its relationship with immune response to viral infections, this study attempted to identify the predictive power of serum vitamin D for poor outcomes among the COVID-19 patients. This retrospective cohort study included all patients with confirmed COVID-19 hospitalized between February 20, 2020, and April 20, 2020, at a designated COVID-19 hospital, located in Tehran province, Iran. General characteristics, medical history and clinical symptoms were recorded by trained physicians. Blood parameters including complete blood count, creatinine, lactate dehydrogenase, creatine phosphokinase, erythrocyte sedimentation rate, C-reactive protein and vitamin D were tested. This study included 290 hospitalized patients with COVID-19 (the mean age [SD]: 61.6 [16.9], 56.6% males), of whom 142 had vitamin D concentrations less than 20 ng/ml, defined as vitamin D deficiency. COVID-19 patients with vitamin D deficiency were more likely to die (Crude OR [95% CI]: 2.30 [1.25-4.26]), require ICU (2.06 [1.22-3.46]) and invasive mechanical ventilation (2.03 [1.04-3.93]) based on univariate logistic regression results. Although, after adjusting for potentials confounders such as gender and age, the association between vitamin D and need to invasive mechanical ventilation lost its significance, adjusted values for the risk of death and ICU requirement were still statistically significant. Vitamin D deficiency can be considered as a predictor of poor outcomes and mortality in COVID-19 patients. Therefore, checking serum 25 (OH) D on admission and taking vitamin D supplements according to the prophylactic or treatment protocols is recommended for all COVID-19 patients.