Oct 24, 2023 16:00:00

Research results show that the ``balance of fungi living in the intestines'' is related to the risk of aggravation of the new coronavirus and long COVID

The human body is inhabited by a huge number of

bacteria and fungi , and these are collectively called the microbiome . A research team from Weill Cornell Medical School and other institutions in the United States has newly discovered that a fungus that lives in the human intestines is associated with the risk of novel coronavirus infection (COVID-19) and long-term COVID -19. Did.

Fungal microbiota sustains lasting immune activation of neutrophils and their progenitors in severe COVID-19 | Nature Immunology
https://www.nature.com/articles/s41590-023-01637-4

Inflammation in severe COVID linked to excess gut fungi
https://www.nature.com/articles/d41586-023-03295-w

Gut Fungi's Lasting Impact on Severe COVID-19 Immune Response | Newsroom | Weill Cornell Medicine
https://news.weill.cornell.edu/news/2023/10/gut-fungis-lasting-impact-on-severe-covid-19-immune-response

Could gut fungi be linked to severe COVID? What to make of new research findings
https://theconversation.com/could-gut-fungi-be-linked-to-severe-covid-what-to-make-of-new-research-findings-216084

The microbiome interacts with the human body in various ways related to health and disease, such as metabolism and immune function, and in recent years, research has focused particularly on the intestinal flora that lives in the intestines. is. It is known that the intestinal flora also interacts with COVID-19, and at the time of writing, more than 700 papers researching the relationship between COVID-19 and the intestinal flora have been published.

In addition, it has been reported that some COVID-19 patients are complicated by fungal infections such as mucormycosis and aspergillosis , and not only the intestinal flora but also the fungal flora and mycobiota that live in the human body are affected by COVID-19. It has been suggested that it may be related to 19.

Therefore, a research team led by

Dr. Ilian Iliev , an immunologist at Weill Cornell Medical School, conducted a study to investigate the relationship between Mycobiota and COVID-19.

First, the research team examined blood samples taken from 91 patients hospitalized with COVID-19 in 2020. Three-quarters of patients developed severe COVID-19 and required more than 6 liters of supplemental oxygen per minute or invasive mechanical ventilation, while the rest had moderate or mild symptoms. thing.

The analysis found that patients with severe COVID-19 were more susceptible to three fungal species, including Candida albicans , a member of the Candida genus , compared to subjects who did not test positive for the novel coronavirus (SARS-CoV-2). It turned out that they produced about four times as many antibodies. The fact that more fungal antibodies were being produced means that the amount of these fungi was increasing in the subjects' bodies.

Analysis of fecal samples taken from 10 patients who developed COVID-19 in early 2021 also showed particularly high levels of Candida spp. compared to healthy individuals. In these COVID-19 patients, the amount of Candida fungi was associated with the severity of COVID-19.

Previous

studies have shown that some fungi, including Candida albicans, activate the immune system. This study also found that the amount of Candida albicans antibodies present in the blood of critically ill patients with COVID-19 was related to the number of immune cells called neutrophils , which cause inflammation in the body.

The research team also conducted experiments comparing mice infected with Candida albicans isolated from severely ill COVID-19 patients and SARS-CoV-2, and mice infected only with SARS-CoV-2. The results confirmed that mice infected with Candida albicans had more neutrophils entering the lungs and more activated inflammatory responses than mice infected only with SARS-CoV-2. This effect was reduced when mice were given an antifungal drug.

They also found that levels of Candida albicans antibodies and neutrophil precursors remained elevated in patients with severe COVID-19 for up to a year after recovery. This suggests that fungi may be involved in long COVID, a known aftereffect of COVID-19.

This study has several limitations to consider, including the small number of participants and the use of samples taken from patients early in the COVID-19 pandemic. However, the finding that the fungus and COVID-19 may be related may have an impact on future COVID-19 treatment and diagnosis.