A SARS-CoV-2 infection changes the gut microbiome, meaning that the immune response in the lungs is also influenced. This has been shown in a recent study.
People infected with Covid have a less diverse gut flora. This was concluded by a Medical Faculty research team at the University of Duisburg-Essen (UDE). In COVID-19 patients, bacteria associated with various inflammatory diseases accumulate; at the same time, there are also fewer anti-inflammatory bacteria. This is shown by the study recently published in Frontiers in Cellular and Infection Microbiology.
Two effects: More enterobacterales and less bifidobacteria
A total of 212 people were examined for the study, 117 people who had a confirmed Corona infection, and 95 people who tested negative and were at the University Medical Centre Essen due to other health problems.
The team was able to observe two effects. Firstly, the number of enterobacterales was increased for people with a Covid infection. This bacteria is usually found in larger amounts in the intestinal flora with multiple inflammatory diseases. At the same time, the amount of bifidobacteria, which is among the key lactic acid producers, was reduced. Additionally, bacteria that produce the short-chain fatty acid (butyrate), which has positive effects on the immune system, occurred less frequently in patients with severe cases of COVID-19. The research team believes it is possible that metabolic products of the intestinal bacteria influence the immune response in the lungs via the blood vessel system.
Indirect connection between the intestine and lungs
There is already evidence in past studies, regarding other diseases, that the gut microbiome influences immune responses in other organs such as the lungs. This is referred to as the gut-lung axis.