Study reveals link between gut health and post-COVID syndrome fatigue

In a recent study, a research team from the Medical University of Vienna has gained new insights into post-COVID syndrome (PCS) and the relevance of a healthy gastrointestinal tract. The study, which was recently published in the journal Allergy, shows that PCS patients have altered inflammatory markers and a disturbed intestinal barrier, which could contribute to the development of post-viral fatigue.

The researchers, led by Eva Untersmayr-Elsenhuber from MedUni Vienna's Center for Pathophysiology, Infectiology and Immunology, analyzed data from a prospective observational study. The course of SARS-CoV-2 infections and gastrointestinal symptoms before, during and after the infection were examined. In addition, blood, saliva and stool samples from PCS patients were analyzed.

The results show that patients with pre-existing gastrointestinal complaints have an increased risk of developing PCS fatigue. At the same time, prominent changes were found in certain biomarkers. For example, PCS patients showed an increased LBP/sCD14 ratio and lower IL-33 levels, which indicates altered immune activation and a reduced intestinal barrier. In addition, there were increased IL-6 levels, which are considered a marker for systemic inflammatory reactions.

Our results suggest that SARS-CoV-2 infection can have long-term effects on the immune system and intestinal health that contribute to the development of PCS."

Eva Untersmayr-Elsenhuber from MedUni Vienna's Center for Pathophysiology, Infectiology and Immunology

She is co-director of the National Reference Center for Postviral Syndromes at MedUni Vienna.

Developing targeted treatment strategies

The study underlines the central role of the gastrointestinal tract in the development of long-term consequences after COVID-19. Monitoring gastrointestinal symptoms and biomarkers could help to identify at-risk patients at an early stage and develop targeted treatment strategies. This could be particularly important for the treatment of post-viral fatigue.

"What is particularly exciting is that our study participants were mostly young and healthy before the infection. Even the Covid disease was mostly mild or even asymptomatic. One difference was the more frequently reported gastrointestinal complaints in the group that developed post-viral fatigue," explains Johanna Rohrhofer from the Center for Pathophysiology Infectiology and Immunology, lead author of the study.

The research team plans to validate the findings in further studies. "The identification of predictive markers for PCS could enable personalized prevention and treatment in the future," says Eva Untersmayr-Elsenhuber.