text: Inflammation type dysbiosis of the oral microbiome associates with the duration of COVID 19 symptoms and long COVID In the COVID 19 pandemic caused by SARS CoV 2 many individuals experience prolonged symptoms termed long lasting COVID 19 symptoms long COVID Long COVID is thought to be linked to immune dysregulation due to harmful inflammation with the exact causes being unknown Given the role of the microbiome in mediating inflammation we aimed to examine the relationship between the oral microbiome and the duration of long COVID symptoms Tongue swabs were collected from patients presenting with COVID 19 symptoms Confirmed infections were followed until resolution of all symptoms Bacterial composition was determined by metagenomic sequencing We used random forest modeling to identify microbiota and clinical covariates that are associated with long COVID symptoms Of the patients followed 63 developed ongoing symptomatic COVID 19 and 37 went on to long COVID Patients with prolonged symptoms had significantly higher abundances of microbiota that induced inflammation such as members of the genera Prevotella and Veillonella which of note are species that produce LPS The oral microbiome of patients with long COVID was similar to that of patients with chronic fatigue syndrome Altogether our findings suggest an association with the oral microbiome and long COVID revealing the possibility that dysfunction of the oral microbiome may have contributed to this draining disease 