Scientists in the UAE have discovered that certain bacteria in the gut can help in reducing the severity of COVID-19 in infected people. A study was conducted by scientists at the University of Sharjah, Khalifa University of Science and Technology in Abu Dhabi, and other institutions, to understand the relationship between the gut microbiome and COVID-19.

According to the study, gut microbiome can significantly influence the severity of the COVID-19 disease and the immune response of the body against the virus. Many studies have analysed the impact of diet and gut microbiome on a person’s ability to tackle Coronavirus.

Research results

Published in Frontiers in Microbiology, the study saw the participation of 86 infected people and an additional 57 without the disease.

The study found that in the group of infected people, there was an increase of some types of disease-causing bacteria in the gut along with an abundance of some bacteria that cause inflammation. As per the researchers, certain bacteria may play a critical role during the early onset of infection among COVID-positive individuals.

Dr Habiba Alsafar, senior author of the study, stated that there is certainty about the impact of pre-existing gut dysbiosis into COVID-19 infection as only those people were sample after they were infected with the virus.

Dr Habiba Alsafar is the director of the Centre for Biotechnology and associate professor of molecular biology and genetics at Khalifa University in Abu Dhabi.

However, in the group of COVID-infected people, there was also a significant number of certain types of anti-inflammatory bacteria along with several types of bacteria that produce butyrate - a fatty acid that can enhance the immune response. Such symbiotic bacteria have a mutually beneficial relationship with the person's immune response.

“Altogether, perhaps the gut symbiotic response plays a significant role in counteracting COVID-19 dysregulated immune response, restoring homeostasis [a stable situation], and subsequently reducing Covid-19 pathogenesis and disease manifestations,” the researchers added.

Role of ACE2 receptors

While COVID-19 is largely a respiratory illness, the gut's immunological function and its microorganisms are notably helpful in effectively responding to infection.

Researchers also underlined that ACE2 receptors are found in some cells lining the intestine. Consequentially, these intestinal cells could be additional sites of SARS-CoV-2 (virus causing COVID-19) infection. ACE2 receptors are particularly found in abundance on cells in the human respiratory system and are considered the attachment points for Coronavirus.

According to Dr Alsafar, the most important connection between the gut microbiome and COVID-19 is the involvement of the ACE2 receptor.

“The ACE2 receptors regulate the gut microbiota, and when a viral infection, like SARS-CoV-2, can enter these receptors, it causes a dysregulation of the intestinal system. Specially formulated probiotics might improve the gut microbiome, although a consultation with a doctor would be required for best results," she added.

Importance of healthy diet

Dr Alsafar further explained that healthier diet which is rich in fruits and vegetables along with more exercise, will impact gut microbe communities.

Results produced by the UAE study are in line with the results developed by a study published earlier this year in the journal Gut. For instance, it was found that lower levels of a butyrate-producing bacterium 'Faecalibacterium' were associated with severe infections. Similar results were discussed by researchers in the UAE study.

Recent study supports previous research

The previous study conducted by researchers in Hong Kong also concluded that the gut microbiome has critical impact on a person’s immune response to Coronavirus infection. Furthermore, it ca also influence the severity of the disease and its eventual outcome.

Researchers also suggested that existing imbalances in the microbiome after COVID-19 infection may result in persistent symptoms observed among people diagnosed with long Covid.

Both the studies conducted by the UAE and Hong Kong add to the existing knowledge developed by a prominent study by King’s College London and Harvard Medical School. It involved hundreds of thousands of people contributing to the data through an app.

As per the study, people with the healthiest diets were 10 percent less likely to develop COVID-19 and 40 percent less likely to become seriously ill from the disease.

Prof Tim Spector from genetic epidemiology at King’s College London explained that people with diets including low levels of ultra-processed foods had healthier gut microbes which helped in combating infection.

“You don’t have to go vegan, but getting more diverse plants on your plate is a great way to boost the health of your gut microbiome, improve your immunity and overall health, and potentially reduce your risk from COVID-19,” he said earlier.