Gut bacteria can influence severity

The gut microbiome plays an important role in health. The intestine is home to billions of microorganisms, including more than 1,000 species of bacteria.

Certain bacteria in the gut help digest food and can also reduce the risk of developing certain diseases.

On the other hand, certain bacteria can contribute to the development of certain types of cancer, play a role in obesity and even have an impact on mental health.

Sometimes the bacteria in the gut can become imbalanced, which scientists call dysbiosis. This can happen as a result of taking antibiotics or following a diet of highly processed foods. Dysbiosis can contribute to the development of health problems.

No two people have the same gut microbiome, but there are certain types of bacteria that everyone could expect to have. This was the basis of the study, co-led by Yun Kit Yeoh. Yeoh works for the Department of Microbiology at the Chinese University of Hong Kong.

Researchers collected blood and stool samples from 100 patients who tested positive for SARS-CoV-2 between February and May 2020 at two hospitals in Hong Kong. They compared the data collected from these people to samples obtained from 78 participants before the start of the pandemic.

The study showed that patients with COVID-19 had higher numbers of certain bacteria, including Ruminococcus gnavus, Ruminococcus pairs, and Bacteroides dorei. R. gnavus, for example, is a bacterium associated with inflammatory bowel disease.

Samples from those with COVID-19 also had a reduced number of other species of bacteria than those without viruses. They had lower counts of Bifidobacterium, Faecalibacterium prausnitzii, and Rectal eubacterium. These species, as the authors explain, have “immunomodulatory potential”.

Additionally, researchers have found elevated levels of cytokines in people with the virus. Cytokines are important for cellular communication; the immune system produces inflammatory cytokines in response to viral infections.

The authors explain that during COVID-19, the body’s inflammatory response can be “too aggressive” and cause a cytokine storm. This can cause “generalized tissue damage, septic shock, and multi-organ failure.”

Overall, the authors conclude: “The associations between gut microbiota composition, cytokine levels, and inflammatory markers in patients with COVID-19 suggest that the gut microbiome is involved in the magnitude of the severity of the disease. COVID-19, possibly via modulation of host immune responses. ”

Researchers say doctors should exercise caution if they decide to use antibiotics to treat someone with COVID-19.

“It is still possible that a higher prevalence of antibiotic administration in severe and critical patients could worsen the inflammation,” the authors write.

They also conclude that “antibiotics are unlikely to be associated with better patient outcomes assuming there are no bacterial coinfections but, in contrast, could exacerbate and prolong gut microbiota dysbiosis in patients. patients with COVID-19. ”

In addition to the gut microbiome contributing to worsening COVID-19 symptoms, researchers believe gut bacteria may play a role in the development of long-lasting COVID.

The authors write that “in light of reports that a subset of recovered patients with COVID-19 have persistent symptoms, such as fatigue, dyspnea [breathlessness] and joint pain, some more than 80 days later [the] initial onset of symptoms, we speculate that the dysbiotic gut microbiome could contribute to immune system-related health issues after COVID-19. “

Knowing that gut health can affect how a person experiences COVID-19, this study can help shape healthcare professionals’ recommendations for precautions. The authors write:

“Boosting beneficial gut species depleted in COVID-19 could serve as a new avenue to alleviate serious disease, highlighting the importance of managing the gut microbiota of patients during and after COVID-19.”