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. 2022 Aug 22;51:17–27. doi: 10.1016/j.clnesp.2022.08.023

Table 2.

A summary of some of the randomized controlled trials registered in ClinicalTrials.gov underway or recruiting that are investigating the application of probiotics for the prevention and/or treatment of COVID-19.

Clinical Trial Identifier Date Posted Study Title Location Study Design Intervention Outcomes Measured Status
NCT04366180 28-Apr-20 Evaluation of the probiotic Lactobacillus coryniformis K8 on COVID-19 prevention in healthcare workers Granada, Spain Randomized parallel assignment Lactobacillus Coryniformis K8 Incidence of infection by PCR or antigen test Completed
NCT04390477 15-May-20 Study to evaluate the effect of a probiotic in COVID-19 Alicante, Spain Randomized parallel assignment Not disclosed Percentage of patients admitted to ICU Completed
NCT04399252 22-May-20 Effect of Lactobacillus on the microbiome of household contacts exposed to COVID-19 North Carolina, United States Randomized parallel assignment Lactobacillus rhamnosus GG Incidence of COVID symptoms during the study period Completed
NCT04517422 18-Aug-20 Efficacy of L. plantarum and P. acidilactici in adults with SARS-CoV-2 and COVID-19 Mexico City, Mexico Randomized parallel assignment Lactobacillus plantarum 30,292,7484 & 7485, & Pediococcusacidilactici Severity progression, ICU duration & mortality ratio Completed
NCT04621071 9-Nov-20 Efficacy of probiotics in reducing duration and symptoms of COVID-19 (PROVID-19) Quebec, Canada Randomized parallel assignment Not disclosed Duration before symptoms disappear Completed
NCT04666116 14-Dec-20 Changes in viral load in COVID-19 after probiotics Valencia, Spain Randomized parallel assignment Bifidobacterium longum, Bifidobacterium animalis subsp. lactis and Lactobacillus rhamnosus Impact on viral load in COVID-19 infected patients Recruiting
NCT04730284 29-Jan-21 Evaluation of a synbiotic formula in patient with COVID-19 Hong Kong Single group assignment Not disclosed Changes in the gut microbiome measured at week 5 Recruiting
NCT04734886 2-Feb-21 The effect of probiotic supplementation on SARS-CoV-2 antibody response after COVID-19 Sweden Randomized parallel assignment Lactobacillus reuteri Specific antibodies in serum associated with SARS-CoV-2 Completed
NCT04756466 16-Feb-21 Effect of the consumption of a Lactobacillus strain on the incidence of COVID-19 in the elderly La Coruña, Spain Randomized parallel assignment Lactobacillus Incidence of infection by PCR or antigen test Active, not recruiting
NCT04854941 22-Apr-21 Efficacy of probiotics in the treatment of hospitalized patients with novel coronavirus infection Moscow, Russia Randomized parallel assignment Lactobacillus rhamnosus, Bifidobacterium bifidum, Bifidobacterium longum Subsp. infantis &Bifidobacterium longum Mortality of patients during hospitalization Completed
NCT04877704 7-May-21 Symprove (probiotic) as an add-on to COVID-19 management London, United Kingdom Randomized single group assignment Multi -Strain Probiotic (Symprove) Length of hospital stay Not yet recruiting
NCT04884776 13-May-21 Modulation of gut microbiota to enhance health and immunity Hong Kong Randomized parallel assignment Probiotics blend (3 Bifidobacteria) Percentage of patients achieving restoration of gut dysbiosis Recruiting
NCT04907877 1-Jun-21 Bifido- and Lactobacilli in symptomatic adult COVID-19 outpatients (ProCOVID) Warsaw, Poland Randomized parallel assignment Mixture of bifido- and lactobacteria Global symptom score Not yet recruiting
NCT04937556 24-Jun-21 Evaluation of a probiotic supplementation in the immune response of participants with COVID-19 (coronavirus disease). (PROVID) Madrid, Spain Randomized parallel assignment Lactobacillus salivarius Concentration of specific antibodies related to SARS-CoV-2 virus Recruiting
NCT04979065 27-Jul-21 Nutrition, immunity, and COVID-19 in obese people (NICO) Jakarta, Indonesia Phase 1: Cross-sectional Phase 2: Double-blind, randomized, placebo-controlled trial with two arms of intervention Probiotics (Strain not disclosed) +Vitamin D Zonulin & Vit D level, gut microbiome, inflammation markers, body mass index (BMI) Not yet recruiting
NCT05043376 14-Sep-21 Study to investigate the treatment benefits of probiotic Streptococcus salivarius K12 for mild-to-moderate COVID-19 Lahore, Pakistan Randomized parallel assignment Streptococcus Salivarius K12 Patients with clinical improvements Recruiting
NCT05080244 15-Oct-21 WHO COVID-19 - evaluation of the efficacy of probiotics to reduce the occurrence of long COVID (PROVID-LD) Quebec, Canada Randomized parallel assignment Not disclosed COVID-19 symptoms, anxiety, functioning difficulties 90 days after the diagnosis Recruiting