Abstract: Microbial Pathogenesis 172 (2022) 105792 Contents lists available at ScienceDirect Microbial Pathogenesis journal homepage: www.elsevier.com/locate/micpath The effect of Nutrition Bio-shield superfood (NBS) on disease severity and laboratory biomarkers in patients with COVID-19: A randomized clinical trial Mehrdad Mosadegh a, *, Aref Khalkhali b, Yousef Erfani c, Manije Nezamdoost d a Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Department of Science, Faculty of Biology, Islamic Azad University, Mashhad, Iran Department of Medical Laboratory Sciences, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran d Department of Internal Medicine, Division of Infectious Disease, Farabi Hospital, Social Security Organization, Mashhad, Iran b c A R T I C L E I N F O A B S T R A C T Keywords: COVID-19 Nutrition bio-shield superfood Laboratory biomarkers Clinical trial study Iran Background: Nutrition Bio-shield Superfood (NBS) is an organic and viable herbal supplement that could improve the function of the immune system. The present study aims to determine the effect of NBS on disease severity and laboratory biomarkers in patients with COVID-19. Methods: This current study was a randomized, comparative, parallel two-arm and single-blind clinical trial study performed in Tehran, Iran. In total, 70 patients with COVID-19 were included in the present study and assigned to two groups including 1) intervention group (n = 35) and 2) control group (n = 35). All patients included in the intervention group received 4.5 gr daily rate of NBS superfood, three times the daily rate of 1.5 gr for 14 days. In contrast, patients included in the control group received a placebo three times a day for 14 days. The mea­ surement of laboratory parameters including CRP, ESR, D-Dimer, LDH, CPK, SGOT, SGPT, ALP, FBG, WBC count, PLT, and lymphocyte count was performed using standard kits and methods. Moreover, all serum samples were tested to determine the levels of IL-6 and TNF-ɑ using specific commercially available ELISA kits according to the instructions of the manufacturer. Results: A significant decrease in the mean serum level of several variables including CRP (p < 0.001), ESR (p < 0.001), D- Dimer (p = 0.001), LDH (p < 0.001), SGOT (p = 0.002), SGPT (p = 0.019), ALP (p < 0.001), WBC count (p < 0.001), body temperature (p = 0.013), IL-6 (p < 0.001), and TNF-α (p < 0.001) was seen 14 days after intervention from baseline in the intervention group than control group. In contrast, in the intervention group, the significant increase from baseline of lymphocyte percentage (p < 0.001) and oxygen saturation (p < 0.001) was seen 14 days after receiving NBS superfood than the control group. Conclusion: Results showed that the use of NBS superfood had various beneficial effects on COVID-19 disease severity. These results suggest that NBS superfood can be used as an effective natural supplement in the treat­ ment process of COVID-19 disease.