Is long COVID triggering irritable bowel syndrome? Arizona study to investigate

Researchers with the ongoing Arizona CoVHORT research study at the University of Arizona Mel and Enid Zuckerman College of Public Health were awarded $3.2 million by the National Institute of Diabetes and Digestive and Kidney Diseases for a five-year study of gastrointestinal symptoms, specifically irritable bowel syndrome, as a condition of long COVID.

Image Credit: Emily frost / Shutterstock

Led by epidemiologist Kristen Pogreba-Brown, PhD, MPH, the CoVHORT study is a longitudinal research study of COVID-19 and post-COVID conditions. The research team is tracking more than 9,000 participants in Arizona to assess long COVID symptoms, post-COVID-19 health impacts, and treatments.

"We have an outstanding team of researchers, staff and students working on the CoVHORT study and investigating a range of long COVID symptoms," Pogreba-Brown said. "And, we have a large, diverse group of participants, so we gather crucial data that deliver answers about specific symptoms, such as irritable bowel syndrome, and help find effective treatments."

Irritable bowel syndrome, or IBS, affects an estimated 10-15% of the U.S. population and can significantly impair quality of life. It is the most common diagnosis of a group of gastrointestinal disorders and is thought to be related to gut-brain interaction.

IBS has been linked to numerous bacterial, protozoan, and viral infections. The risk of developing IBS following an acute gastrointestinal, or GI, infection is approximately 9%. Notably, COVID-19 infection elicits a wide range of GI symptoms, including diarrhea, nausea, and vomiting, with reports of acute GI symptoms occurring in more than 60% of patients.

Understanding how COVID-19 impacts the incidence of IBS or exacerbates IBS symptoms has the potential to benefit millions of people, given the scale of the pandemic and ongoing waves of infection, with many reports of chronic GI symptoms after acute COVID-19 infection.

The study, "Determining the Incidence, Risk Factors and Biological Drivers of Irritable Bowel Syndrome (IBS) as Part of the Constellation of Post-Acute Sequelae of SARS-CoV-2 Infection (PASC) Outcomes," will take advantage of the Arizona CoVHORT study's unique scope and infrastructure to deliver vital data to better evaluate and treat COVID-19-related IBS.

The new research will:

1. Estimate the incidence of IBS and other GI conditions in participants after COVID-19 infections compared with participants who have not had COVID-19.
2. Determine the role of pre-existing IBS on the development and severity of post-COVID-19 symptoms.
3. Establish mechanisms of IBS following COVID-19 infections, including differences in the fecal microbiome composition and function, the individual's anti-commensal immune response to the fecal microbiome, and targeted/untargeted serum protein biomarkers among participants who were exposed to COVID-19 and those who were not and participants who do and do not develop IBS.

"The awareness of long-COVID and post-COVID-19 health complications has diminished since the pandemic has receded, and yet millions of people still suffer," said Iman Hakim, MD, Ph.D., MPH, dean of the Zuckerman College of Public Health, "The CoVHORT research study continues to find answers about long COVID and the symptoms that follow infection – knowledge we can use to find treatments. This is public health in action. I'm so proud of Dr. Pogreba-Brown and her team for the work they do that will improve health for people in the United States and around the world."