Evaluation of fecal bacterioma and correlation with systemic inflammatory markers in patients infected with SARS-CoV-2

Abstract

COVID-19 is an infectious disease caused by the coronavirus associated with severe acute respiratory syndrome 2 (SARS-CoV-2). According to the World Health Organization, SARS-CoV-2 has infected more than 761 million people worldwide, with more than 6.88 million deaths. So far, in Brazil, there are more than 37 million confirmed cases and 699,634 deaths. The disease comprises a wide spectrum of clinical manifestations, ranging from asymptomatic to critically ill patients, with involvement not only of the respiratory tract, but also the gastrointestinal tract. Massive production of inflammatory cytokines has been associated with the progression of COVID-19 to severe cases, and the development of severe acute respiratory syndrome, coagulation dysfunction and multiple organ system failure. The patient's immune status can determine the immune response against SARS-CoV-2, and both, the immune status and the clinical response can be influenced by the intestinal microbiota. Therefore, the aim of this study will be to evaluate the fecal bacterioma in patients with acute COVID-19 and correlate it with systemic inflammatory markers and clinical data. This project was approved by the Research Ethics Committee (Processes nº 4.310.336/2020; nº 4.688.359/2021) and all participants signed the informed consent form. The fecal bacterioma will be evaluated by 16S sequencing, and inflammatory markers by flow cytometry. The identification of biomarkers associated with intestinal dysbiosis and immune dysregulation can help predict severe/critical cases of COVID-19, helping to formulate protocols for rapid intervention. So far, our study presents a number of patients included greater than that presented in the international literature (acute COVID-19 = 101; and controls = 91) and will significantly contribute to the identification of factors involved in the progression of the disease to severe cases.