Abstract: Since January 2020 Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre - including this research content - immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active. International Immunopharmacology 95 (2021) 107531 Contents lists available at ScienceDirect International Immunopharmacology journal homepage: www.elsevier.com/locate/intimp The role of probiotics in coronavirus disease-19 infection in Wuhan: A retrospective study of 311 severe patients Qiang Li 1, Fang Cheng 1, Qiling Xu , Yuyong Su , Xuefeng Cai , Fang Zeng *, Yu Zhang * Department of Pharmacy, Union Hospital, Tongji Medical College, Hua Zhong University of Science and Technology, Wuhan 430022, China Hubei Province Clinical Research Center for Precision Medicine for Critical Illness, Wuhan 430022, China A R T I C L E I N F O A B S T R A C T Keywords: COVID-19 Probiotics Immunity Inflammatory Purpose: Researches revealed that probiotics maybe a potential strategy for COVID-19, whereas there is a lack of related evidence. This study aims to analyze the role of probiotics on severe COVID-19 patients. Methods: In the current retrospective single-center study, we collected data of 311 consecutive severe patients with confirmed COVID-19 in Wuhan Union Hospital from Feb 3rd to Feb 20th, 2020. Epidemiological, clinical and medication characteristics were compared and analyzed between patients with or without probiotics. Results: In total, 93 of the 123 patients (75.61%) who were treated with probiotics survived to hospital discharge with the median inpatient day of 32 days and mean virus clearance time of 23 days, which were significantly longer than those of patients without probiotics. There were no bias in laboratory parameters, except for IL-6 and ESR, which were significantly higher in patients treated probiotics. We tracked the dynamic changes of 8 selected laboratory parameters (IL-6, CRP, total T lymphocytes, NK cells, B lymphocyte, CD4 + T cells, CD8 + T cells and CD4/CD8 ratio) and found that probiotics could not reduce the increased IL-6 levels but possessed the ability to moderate the immunity and decreased the incidence of secondary infection in COVID-19 patients. Conclusions: Probiotics could be an effective strategy for the treatment of COVID-19 patients to reduce the secondary infection and moderated the immunity.