Determining the incidence, risk factors and biological drivers of irritable bowel syndrome (IBS) as part of the constellation of postacute sequelae of SARS-CoV-2 infection (PASC) outcomes in the Arizona CoVHORT-GI: a longitudinal cohort study.

Introduction: Postacute sequelae of SARS-CoV-2 infection (PASC) are extensive. Also known as long COVID, primary outcomes reported are neurologic, cardiac and respiratory in nature. However, several studies have also reported an increase in gastrointestinal (GI) symptoms and syndromes following COVID-19. This study of PASC will include extensive analyses of GI symptoms, determine if people with pre-existing irritable bowel syndrome (IBS) are at higher risk of developing PASC generally or PASC-GI, and which biomarkers are impacted and to what degree. This R01 study is being funded by the National Institute of Diabetes and Digestive and Kidney Diseases (1R01DK135483-01) from 2023 to 2028.

Methods and analyses: This study combines a longitudinal epidemiologic cohort study and in-depth, novel biologic analyses. In collaboration with a pre-existing study, the Arizona CoVID-19 Cohort (CoVHORT)-GI will recruit participants based on the history of COVID infection(s), new or ongoing GI symptoms 3-6 months postinfection, and pre-existing or incident IBS diagnosis to represent five study groups for comparison and analyses. A subset (n=1000) of those recruited will submit both stool and blood samples. Both samples will undergo a novel method to quantitate humoral and mucosal immune responses to host-derived faecal communities in conjunction with magnetic bead-based separation and high-depth shotgun microbial sequencing. Stool samples will also undergo traditional microbiome analyses (diversity and abundance) and faecal calprotectin assays. Additional serum analyses will aim to determine if a proteomics-based signature exists that differentiates a unique biomarker compositional signature discriminating PASC-GI versus no PASC. All laboratory data will be linked with in-depth epidemiologic data on demographics, symptoms and chronic conditions.

Ethics and dissemination: This study involves human participants and was approved by the University of Arizona Institutional Review Board (IRB (#00002332) and has been deemed minimal risk. Participants gave informed consent to participate in the study before taking part. All publications from the study will be shared back to participants along with alternative lay summaries and webinars to communicate key findings. The data management plan has been published and is publicly available online, including protocols for data requests.