Effect of an Immune-Boosting, Antioxidant and Anti-Inflammatory Food Supplement in Hospitalized COVID-19 Patients: A Prospective Randomized Pilot Study

Background: COVID-19 disease is a serious global health problem. Few treatments have been shown to reduce mortality and accelerate time to recovery. The aim of this study was to evaluate the potential effect of a food supplement (probiotics, prebiotics, vitamin D, zinc and selenium) in patients admitted with COVID-19. Methods: A prospective randomized non-blinded clinical trial was conducted in a sample of 162 hospitalized patients diagnosed with COVID-19 recruited over eight months. All patients received standard treatment, but the intervention group (n = 67) was given one food supplement stick daily during their admission. After collecting the study variables, a statistical analysis was performed comparing the intervention and control groups and a multivariate analysis controlling for variables that could act as confounding factors. Results: ROC curve analysis with an area under the curve (AUC) value of 0.840 (p < 0.001; 95%CI: 0.741–0.939) of the food supplement administration vs. recovery indicated good predictive ability. Moreover, the intervention group had a shorter duration of digestive symptoms compared with the control group: 2.6 ± 1.3 vs. 4.3 ± 2.2 days (p = 0.001); patients with non-severe disease on chest X-ray had shorter hospital stays: 8.1 ± 3.9 vs. 11.6 ± 7.4 days (p = 0.007). Conclusions: In this trial, the administration of a food supplement (Gasteel Plus(®)) was shown to be a protective factor in the group of patients with severe COVID-19 and allowed early recovery from digestive symptoms and a shorter hospital stay in patients with a normal–mild–moderate chest X-ray at admission (ClinicalTrials.gov number, NCT04666116).