{"id":2100,"date":"2023-03-09T09:35:22","date_gmt":"2023-03-09T09:35:22","guid":{"rendered":"https:\/\/website.prod.unilu.spikeseed.cloud\/fr\/news\/shifts-in-human-gut-microbiome-due-to-covid-19\/"},"modified":"2023-03-09T09:35:22","modified_gmt":"2023-03-09T09:35:22","slug":"shifts-in-human-gut-microbiome-due-to-covid-19","status":"publish","type":"news","link":"https:\/\/www.uni.lu\/fr\/news\/shifts-in-human-gut-microbiome-due-to-covid-19\/","title":{"rendered":"Shifts in human gut microbiome due to COVID-19"},"content":{"rendered":"

COVID-19, caused by an infection with the SARS-CoV-2 virus, was declared a global pandemic by the World Health Organisation (WHO) in March 2020.\u00a0\u00a0While some people developed severe illness and required medical care, many people reported only mild-to-moderate symptoms, if any at all. However, many of the infected individuals have experienced persisting symptoms or frequent other infections months after the initial infection even if they weren\u2019t much impacted by the disease to begin with. Particularly with the emergence of new variants, many patients\u00a0also reported gastrointestinal symptoms. Researchers from the University\u2019s Luxembourg Centre for Systems Biomedicine and the Luxembourg Institute of Health investigated the impact of mild-to moderate COVID-19 on the compositions and functionalities of the gut microbiome. Their results show an increased\u00a0infective competence<\/i>\u00a0in the microbiome of COVID-19 individuals and these have recently been published in the scientific journal\u00a0Microbiome<\/i>.<\/p>

Impact on the gut microbiome\u2019s infective competence<\/strong><\/p>

Severe SARS-CoV-2 infections were found to be associated with alterations to the gut microbiome\u00a0which may persist for at least six months after the initial infection [1]. Imbalances in the gut microbiome may also be a predisposing factor to bacterial, viral, or fungal co-infections. \u201cIntensive research during the past three years has revealed important mechanisms of the disease overall. However, the gut microbiome had so far only been investigated in severe COVID-19 cases,\u201d explains Prof. Paul Wilmes, head of the Systems Ecology group at the University of Luxembourg and senior author of the study. \u201cTogether with colleagues from the Luxembourg Institute of Health, we wanted to understand if microbiome alterations are unique to severe disease or a common effect of COVID-19 and whether they could play a role in the long-term effects that many patients experience.\u201d<\/p>

The researchers analysed stool samples obtained from individuals with mild-to-moderate COVID-19 and healthy control subjects of Luxembourg\u2019s Predi-COVID and CON-VINCE cohort studies, respectively. The researchers found that there was no significant difference between\u00a0the patients\u00a0and healthy individuals in the overall composition of microbial taxa. This\u00a0suggests that asymptomatic-to-moderate disease likely does not lead to significant changes in the structure of the human gut microbiome. However,\u00a0patients with\u00a0asymptomatic-to-moderate\u00a0COVID-19 showed an altered\u00a0infective competence<\/i>. \u201cWe\u00a0found an increased abundance and expression of virulence factors in COVID-19 individuals. These are factors that help bacteria to invade and colonise the host,\u201d details Dr Laura de Nies, co-first author of the study. \u201cIn addition, we saw an increased abundance and expression of antimicrobial resistance genes which determine bacterial resistance to antibiotics in patients.\u201d The significant association between abundances and expression of virulence factors and antimicrobial resistance genes in individuals with COVID-19 indicates an increased capacity for infection within the gut microbiome. In this context two commensal families (Acidaminococcaceae and Erysipelatoclostridiaceae) had significantly higher prevalence in COVID-19 compared to healthy individuals suggesting that SARS-CoV-2 infection may switch their behaviour from protective to potentially harmful for the host. In addition to the changes of bacterial composition, the study also showed an increased abundance and expression of betaherpesvirus and rotavirus C genes in people with COVID-19. Additional follow-up studies are needed to elucidate if gastrointestinal symptoms are caused by the SARS-CoV-2, altered infective competence and\/or co-infections with other viruses.<\/p>

\u201cOur study indicates that COVID-19\u2019s influence on the\u00a0infective competence<\/i>\u00a0of the gut microbiome may lead to a higher likelihood for other infections,\u201d concludes Paul Wilmes. He is confident that this study paves the way for future research that may use these findings to track and unravel potential links to longer-term effects of COVID-19 and to study whether changes in\u00a0infective competence<\/i>\u00a0are a common feature of viral and bacterial infections.<\/p>

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This study has been conducted as a collaborative effort within Research Luxembourg supported by the Luxembourg National Research Fund (FNR), the Ministry of Higher Education and Research, and\u00a0the Fondation Andr\u00e9 Losch.\u00a0<\/p>

It is based on the following COVID-19 cohort studies in Luxembourg:<\/p>