New York University Study Finds That SARS-CoV-2 Infection Causes Gut Microbiome Dysbiosis That Increases Risk For Bacterial Infections!
A new study led by researchers from New York University Grossman School of Medicine – USA along with scientist from Yale University -USA has found that SARS-CoV-2 infections causes gut microbiome dysbiosis which in turn increases the risk for bacterial infections!
Despite numerous studies showing that microbial populations in the gut microbiome are associated with COVID-19 severity, a causal impact on patient health has not been established.
The study team in their new research provides evidence that gut microbiome dysbiosis is associated with translocation of bacteria into the blood during COVID-19, causing life-threatening secondary infections.
The study team first demonstrated SARS-CoV-2 infection induces gut microbiome dysbiosis in mice, which correlated with alterations to Paneth cells and goblet cells, and markers of barrier permeability.
Subsequently, samples collected from 96 COVID-19 patients at two different clinical sites also revealed substantial gut microbiome dysbiosis, including blooms of opportunistic pathogenic bacterial genera known to include antimicrobial-resistant species.
Detailed analysis of blood culture results testing for secondary microbial bloodstream infections with paired microbiome data indicates that bacteria may translocate from the gut into the systemic circulation of COVID-19 patients.
The study findings are consistent with a direct role for gut microbiome dysbiosis in enabling dangerous secondary infections during COVID-19.
The study findings were published in the peer reviewed journal: Nature.
The study findings show that typically, infection with SARS-CoV-2 coronavirus, the causative agent of the COVID-19 pandemic, can decrease the number of bacterial species in a person’s gut. This reduced microbiome diversity creates space for dangerous microbes to thrive.
The research revolves on the realization that in recent decades the widespread use of antibiotics to fight infections with disease-causing bacteria killed off species most vulnerable to available drugs, leaving in place more species that are resistant to antibiotics. Furthermore, disruptions in gut bacterial ratios have previously been linked to more severe COVID-19.
To date it has remained unclear which came first, according to study team. Does the coronavirus infection disrupt the gut microbiome or is an already weakened gut making the body more vulnerable to the virus?
The study findings now appear to favor the former explanation. The new investigation also revealed that antibiotic-resistant species can escape into the bloodstream, putting patients at greater risk for life-threatening secondary infections.
The clinical study involved 96 men and women hospitalized with COVID-19 in 2020 in New York City and in New Haven, Connecticut, and was led by researchers at New York University Grossman School of Medicine.
Study findings showed that the majority of patients had low gut microbiome diversity, with a full quarter dominated by a single type of bacteria.
Alarmingly, the study findings also showed that at the same time, populations of several microbes known to include antibiotic-re
sistant species increased, possibly due to widespread antibiotic use early in the pandemic.
Worryingly, it was also found that in 20% of patients, these antibiotic-resistant bacteria found in the gut were also observed to have migrated into the bloodstream.
The research team notes that further research is warrnated to uncover why this group was at higher risk for a secondary infection while others remained protected.
Co-corresponding author, Dr Ken Cadwell, PhD, a microbiologist at the Division of Gastroenterology, Department of Medicine, New York University Grossman School of Medicine told Thailand Medical News
“Our findings suggest that coronavirus infection directly interferes with the healthy balance of microbes in the gut, further endangering patients in the process. Now that we have uncovered the source of this bacterial imbalance, physicians can better identify those coronavirus patients most at risk of a secondary bloodstream infection.”
This is the first study to show that the coronavirus infection alone, and not the initial use of antibiotics to treat the disease as other experts had thought, damages the gut microbiome.
Dr Cadwell, who is also a professor in the Departments of Microbiology and Medicine at NYU Langone Health adds the study also provides the first evidence that the very same bacteria in the gut are also entering the bloodstream of patients, causing dangerous infections.
For the study, the research team first infected dozens of mice with the SARS-CoV-2 coronavirus and analyzed the makeup of bacterial species in their stool samples. This step allowed them to untangle whether the coronavirus could directly disrupt the microbiome independently of hospitalization and treatment.
The study team next collected stool samples and blood tests from COVID-19 patients at NYU Langone Health and Yale University hospitals to assess gut microbe composition and the presence of secondary infection. If any bacteria group made up a majority of the bacteria living in the gut, they were considered dominant.
Senior author Dr Jonas Schluter, PhD, an assistant Professor in the Department of Microbiology at NYU Langone and a member of its Institute for Systems Genetics added, “Our study findings highlight how the gut microbiome and different parts of the body’s immune system are closely interconnected. An infection in one can lead to major disruptions in the other!”
Dr Schluter however cautions that since the patients received different kinds of treatments for their illness, the investigation could not entirely account for all factors that may have contributed to the disruption of their microbiome and worsened their disease.
The study team next plans to examine why certain microbial species are more likely to escape the gut during COVID-19. The researchers say they also intend to explore how different microbes interact, which may contribute to this migration into the bloodstream.
For the latest COVID-19 Research
, keep on logging to Thailand Medical News