Alterations of the oral and gut mycobiome and cytokines during long-term follow-up of COVID-19 convalescents

A large number of COVID-19 patients experience body-specific conditions such as fatigue, sleep disturbances, anxiety, depression, and dyspnea after the disease has subsided, which is called “long COVID-19”. 1 Studies have confirmed reduced microbial diversity, enrichment of opportunistic pathogens and depletion of beneficial symbiotic bacteria in patients with COVID-19. 2 , 3 Long-term dysregulation of the microbiota has also been observed in recovered patients. 4 Nevertheless, long-term fungal microbiota follow-up was still blank. The microecology is closely associated with altered immune status and physical health and may be a potential cause of symptoms. We collected tongue coating, feces, and serum samples from 35 COVID-19 confirmed patients who were recovery (CPR0) and followed up for 1 year (CPR1) and 90 age- and sex-matched healthy controls (HC) for internal transcribed spacer (ITS) sequencing (Supplementary Fig. 1 , Supplementary Table S1 ). The blood routine, liver and kidney function, and cytokines of CPR1 and HC were all within the normal range, but a few indicators were different, and most of them in the HC group were lower (Supplementary Tables S2 – 3 ).