Antiviral Activity of Probiotics in the Prophylaxis and Treatment of Respiratory Infections Associated with Coronavirus (COVID-19): A Meta-Analysis of Randomized Controlled Trials

Introduction: Probiotics, living microorganisms administered in sufficient quantities, exert beneficial effects on host health. Given the high prevalence of SARS-CoV-2, recent studies suggest potential positive impacts of probiotics on COVID-19 patients. Methods: A predetermined search strategy encompassing seven databases, NCBI, PubMed, Science Direct, Springer Link, Embase, CNKI, and Cochrane Library Databases, was implemented. Human RCTs were scrutinized independently for data extraction, quality and risk of bias assessment, and statistical analysis. Pooled data, employing the random-effects model, are expressed as standardized mean differences (SMDs) with 95% confidence intervals (CIs). Assessments of the p value and heterogeneity (I²) were conducted and quantified. Results: Five studies comprising 282 out of 375 participants were included. The meta-analysis revealed effects on various parameters: CRP level (SMD=0.26 MG/L, 95% CI [0.10, 0.43], p= 0.002, (I²=67%, p=0.03); BMI (SMD=0.28 KG/m², 95% CI [0.07, 0.50], p= 0.01, (I²=67%, p=0.40); T-cell count (SMD=0.09 G/L, 95% CI [-0.07, 0.26], p= 0.26, (I²=0%, p=0.73); Albumin level (SMD=0.28 G/DL, 95% CI [0.04, 0.52], p= 0.02, (I²=7%, p=0.34); IL-6 level (SMD=0.67, 95% CI [0.45, 0.90], p= 0.00001, (I²=94%, p=0.0001)); and LDH level (SMD=0.12 mmol/L, 95% CI [-0.05, 0.30], p= 0.17 Conclusion: This meta-analysis suggested that probiotics had significant positive effects on various measures for treating COVID-19.