While COVID-19 primarily affects the respiratory system, new research shows it has a significant impact on other organs including gut health.
A study by King's College London has shown severe disruptions in the small intestine as a consequence of COVID-19.
The system that regulates the composition of the microbial communities - otherwise known as Peyer's patches - were severely disrupted in patients suffering from severe COVID-19.
Peyer's patches are groups of lymphoid follicles in the small intestine. They are present in the mucus membrane of the small intestine. They showed dysregulation irrespective of whether the SARS-CoV-2 virus had made its way to the gut or not.
The Gut and COVID-19 Immunity
The link between COVID-19 and altered gut function has been studied earlier as well.
While severe COVID-19 can lead to breathing problems and high fever, some patients can experience diarrhoea, nausea and vomiting, which points at disruptions to the gastrointestinal tract.
"In severe COVID-19, gut health is disrupted, whether the intestine itself is infected with SARS-CoV-2 or not, and this leads to disturbances in the intestinal microbial population."Jo Spencer, Professor, King's College London
The study, published in the Frontiers in Immunology journal, analysed gastrointestinal tract samples from patients who died after being diagnosed with COVID-19 in the first wave of the pandemic.
The study also found that changes in the structure and cellularity in Peyer's patches happened independent of the local concentration of the virus.
COVID-19's Long-Term Impact on Gut Health
The long-term impact of COVID-19 on the gut included depletion of the germinal centres, which normally propagate antibody producing cells, in patients who died with COVID-19.
Lymphoid tissue in the gut normally maintains healthy intestinal microbial populations which are essential for good health.
The resulting poor local immunity could lead to a reduction in microbial diversity in the gut, known as dysbiosis.
Researchers also noted that the findings suggest that oral vaccination may not be effective if the patient is already ill, as the gut immune system is already compromised.
"In the future it will be important to understand factors driving such lymphoid tissue dysregulation in severe inflammatory responses," Spencer said.
(With inputs from IANS)