Evaluation of Lactobacillus Coryniformis K8 Consumption by Health Care Workers Exposed to COVID-19 (LactoCor2 Project): Protocol for a Randomized Controlled Trial

BACKGROUND: Lactobacillus coryniformis K8 CECT5711 has immune-modulating properties, enhances the immune response to viral antigens leading to the production of specific antibodies, and has anti-inflammatory activity, which may help to prevent uncontrolled inflammatory processes leading to respiratory and other organ failures. OBJECTIVE: The purpose of this study is to evaluate the effect of the consumption of a probiotic strain on the incidence and severity of COVID-19 in health personnel who carry out their professional work among patients with infection or suspected infection by SARS-CoV-2. METHODS: This is a double-blind randomized clinical trial in which the experimental group will receive a capsule of L coryniformis K8 per day (3×10(9) colony former units/day), and the control group will receive a daily placebo capsule consisting of maltodextrin. A sample size of 314 volunteers was calculated. Volunteers must meet the following inclusion criteria: older than 20 years and active health personnel caring for patients with COVID-19, including all professionals such as medical doctors, nurses, and caretakers at the 2 referral hospitals that treat patients with COVID-19. The main outcome of the clinical trial will be the incidence of symptomatic infection by SARS-CoV-2 in personnel who care for patients with suspected or confirmed COVID-19. RESULTS: The study had to be extended to the 2 referral hospitals that treat patients with COVID-19 in the province of Granada (Andalusia, Spain); Hospital San Cecilio and Hospital Virgen de las Nieves. A total of 255 individuals met the inclusion criteria and were randomly assigned to one of the 2 groups. CONCLUSIONS: The results of this randomized controlled trial will provide valuable information regarding the administration of L coryniformis K8 against COVID-19, including whether there are fewer infectious processes due to this virus or, in case of occurrence, whether the disease is milder in participants taking the probiotic strain. TRIAL REGISTRATION: ClinicalTrials.gov NCT04366180; http://www.clinicaltrials.gov/ct2/show/NCT04366180 INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR1-10.2196/37857