A recent study involving over 700 individuals has revealed notable differences in the bacteria found in the mouths and lungs of those suffering from long Covid. The findings, published in the European Respiratory Journal, highlight a connection between the lung microbiome differences and the respiratory issues, along with cognitive and digestive problems associated with long Covid.
Researchers believe that understanding these microbiome changes could help explain why some people develop long Covid and might even pave the way for new treatment options. Dr. Daniela Alferes de Lima Headley from the University of Dundee in the UK led this research, emphasizing the need to explore the microbiome’s role in health, particularly since long Covid impacts multiple organs.
Dr. Headley stated, “Millions around the world are still dealing with the effects of long Covid, and we still don’t fully understand its causes. Since Covid primarily affects the lungs, it makes sense to investigate changes in the lung microbiome as part of understanding this condition.”
This study is part of the PHOSP-COVID project, funded by the National Institute for Health and Care Research (NIHR) and UK Research and Innovation. The research focused on 771 patients treated for Covid-19 in various UK hospitals between February 2020 and March 2021. Participants were classified into four groups based on the severity of their symptoms five months after discharge: very severe, severe, moderate, and mild.
After six months, saliva and sputum samples were collected from patients to analyze the types and quantities of microbes present. The results indicated that individuals with the most severe long Covid exhibited significant differences in their oral and lung microbiomes compared to those without severe symptoms. These differences were linked to various issues, including reduced lung function, cognitive challenges often referred to as “brain fog,” and digestive problems.
One notable finding was an increase in lactic acid-producing bacteria associated with signs of inflammation in the patients’ blood samples. Professor James Chalmers from the University of Dundee, who led the study, remarked, “We found that the patients with the most severe symptoms had marked changes in the microbiome, not just in their lungs but also linked to other symptoms such as cognitive and gut issues.”
Professor Chalmers also pointed out the need for further research to determine whether these microbiome changes occur before or after a Covid infection and how they might alter over time. “We must urgently understand the causes of long Covid to address this significant healthcare issue,” he stated.
The PHOSP-COVID initiative continues to explore strategies for understanding and managing long Covid, including the role of inflammation in the condition. Professor Raquel Duarte, who heads an assembly on infectious diseases at the University of Porto, noted that many people are still coping with the long-term effects of Covid, which can severely impact their daily lives. She highlighted the importance of this study, saying it provides valuable insights that could guide future research and treatment approaches for those suffering from long Covid.
