Antiviral Activity of Probiotics in the Prophylaxis and Therapy of Respiratory Infections Associated with Coronavirus (COVID-19): 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 studies were scrutinized independently, involving data extraction, quality and risk of bias assessment, and statistical analysis. Pooled data, employing the random-effects model, were expressed as Standardized Mean Differences (SMD) with a 95% Confidence Interval (CI). Assessments of (p) value and heterogeneity (I²) were conducted and quantified. Results Five studies, comprising 282 out of 375 participants, were included. Meta-analysis revealed effects on various parameters: CRP (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-cells (SMD = 0.09 G/L, 95% CI [-0.07, 0.26], p  = 0.26, (I²=0%, p  = 0.73)), Albumin (SMD = 0.28 G/DL, 95% CI [0.04, 0.52], p  = 0.02, (I²=7%, p  = 0.34)), IL-6 (SMD = 0.67, 95% CI [0.45, 0.90], p = 0.00001, (I²=94%, p  = 0.0001)), LDH (SMD = 0.12mmol/L, 95% CI [-0.05, 0.30], p  = 0.17, (I²=55%, p  = 0.13)), and Ferritin (SMD = 0.19mmol/L, 95% CI [-0.27, 0.66], p  = 0.41, (I²=77%, p  = 0.04)). Conclusion This meta-analysis suggests significant positive effects of probiotics on various measures for COVID-19 treatment.