Gastrointestinal symptoms of long COVID relate to the ectopic colonization of specific bacteria that move between the upper and lower alimentary tract (part 2bM)

We prospectively collected saliva samples from patients with mild COVID-19 who had not been treated with antibiotics and followed up for 3 months after discharge. Paired saliva samples were collected from these patients and healthy controls at a 3-month follow-up. Saliva samples collected from 45 patients during hospitalization, after 3 months, and healthy controls were analyzed by 2bRAD microbiome sequencing (2bRAD- m).