Description: A groundbreaking study reveals how certain nasal bacteria influence COVID-19 susceptibility through viral entry protein gene expression.
The Hidden Influence of Nasal Bacteria on COVID-19 Risk
As the world grapples with the complex landscape of COVID-19, a new study sheds light on an unexpected player in the pandemic: the bacteria residing in our nasal cavities. This groundbreaking research from the George Washington University uncovers a compelling connection between nasal microbiome composition and the body’s susceptibility to COVID-19. Understanding this relationship could pave the way for novel prevention strategies, enhancing our approach to combating respiratory infections.
We’ve known that the virus SARS-CoV-2 enters the body through the respiratory tract, with the nose being a key entry point. What’s new-and surprising-is that bacteria in our noses can influence the levels of proteins that the virus uses to infect cells.”
~Cindy Liu, associate professor of environmental and occupational health, GW Milken Institute School of Public Health
Key Findings from the Study
Higher Gene Expression Correlates with Increased Risk
In a detailed analysis of nasal swab samples from over 450 individuals, researchers found noteworthy differences in gene expression levels related to COVID-19 risk:
- Viral Entry Proteins: The study identified higher levels of gene expression for two crucial proteins—ACE2 and TMPRSS2—in those who later tested positive for COVID-19.
- ACE2 is the receptor that allows the virus entry into nasal cells.
- TMPRSS2 plays a role in activating the virus by cleaving its spike protein.
- Risk Assessment: Individuals with elevated expression of these proteins were:
- More than three times as likely to test positive for COVID-19.
- Those with moderate levels had a doubled risk.
Furthermore, fluctuations in gene expression were observed, with sharp increases noted just days prior to positive test results, suggesting that rising expression levels could indicate heightened vulnerability.
Gender-Specific Insights
Interestingly, the study noted that while women exhibited generally higher gene expression levels of these proteins—aligning with previous findings of higher COVID-19 infection rates among women—men presenting with elevated levels faced a greater risk of infection. This finding emphasizes the need for gender-specific considerations in understanding COVID-19 vulnerability.
The Role of Nasal Bacteria in COVID-19 Risk
With insights into gene expression patterns, the researchers turned their focus to the nasal microbiome—the vast community of bacteria that inhabit our noses. Their findings revealed:
- Certain nasal bacteria may influence the expression of ACE2 and TMPRSS2, thereby impacting susceptibility to COVID-19.
- Notable bacteria linked to increased risk included:
- Staphylococcus aureus
- Haemophilus influenzae
- Moraxella catarrhalis/nonliquefaciens
Conversely, a bacterium named Dolosigranulum pigrum was associated with lower expression levels of these critical proteins, potentially offering some protective effects against the virus.
“Some bacteria in your nose may be setting the stage—or even holding the door open—for viruses like SARS-CoV-2 to get in,” said Daniel Park, a senior research scientist and the study’s first author.
With 20% of participants carrying sufficient S. aureus to nearly double their risk for elevated ACE2 and TMPRSS2 expression, it stands out as a significant risk factor within the nasal microbiome.
Implications for Future Research
The findings of this study open new avenues for predicting and preventing COVID-19 infections. The potential for monitoring ACE2 and TMPRSS2 gene expression could lead to identifying individuals at heightened risk.
Additionally, the research underscores the possibility of modifying the nasal microbiome through methods such as nasal sprays or live biotherapeutics, helping to deter viral infections and perhaps paving the way for proactive strategies in future pandemics.
“We’re only beginning to understand the complex relationship between the nasal microbiome and our health,” Liu remarked, emphasizing the study’s contribution to ongoing investigations.
Note: This article is a reimagined presentation of original research. No factual content or interpretation has been altered in any way.
The study, titled The Nasal Microbiome Modulates Risk for SARS-CoV-2 Infection, was published on April 9 in the journal EBioMedicine. It received support from the GW Milken Institute School of Public Health and the National Institutes of Health.
For further details, refer to the original publication here.
