Clinical Research Directory

Inclusion Criteria: * Willing and able to provide written informed consent, and * Age \>/= 18 years, and * Either: History of a SARS-CoV-2 infection resulting in Long COVID symptoms, confirmed by the investigator, or Exposure to SARS-CoV-2 without establishment of Long COVID. * Enrolled or willing to enroll and complete at least 1 visit in the UCSF Long-term Impact of Infection with Novel Coronavirus (LIINC). * Enrolled or willing to be referred for a gut biopsy procedure under related IRB-approved protocols. Exclusion Criteria: * Self-reported or documented chronic anemia with hemoglobin \< 9 g/dL. Anemia during a preceding acute illness will not be exclusionary. * Serious medical or psychiatric illness that, in the opinion of the site investigator, would interfere with the ability to adhere to study requirements or to give informed consent. * Presence of a condition or abnormality that in the opinion of the Investigator would compromise the safety of the patient or the quality of the data.