Common Fungal Compound May Be the Key to Fighting Deadly Flu Infections

Preclinical trial reveals how beta-glucan, a compound found in all fungi, can ‘reprogram’ immune cells to combat lung inflammation.

A recent study suggests that a common fungal component may help protect against flu-related lung damage.

Led by Professor Maziar Divangahi from McGill’s Faculty of Medicine and Health Sciences and the Research Institute of the McGill University Health Centre, the research team found that beta-glucan, when given to mice before influenza exposure, reduced lung damage, improved lung function, and lowered the risk of severe illness and death.

Beta-Glucan and Immune Defense

Beta-glucan is found in all fungi, including mushrooms and yeast, as well as grains like oats and barley. The scientists discovered that a unique structure of this component can boost defenses against pathogens.

While most research focuses on stopping the virus from replicating, this study explored how to regulate the body’s immunity to infection, a concept known as “disease tolerance.” The researchers discovered that beta-glucan significantly enhanced flu survival rates by modulating immune responses and preventing severe lung inflammation, a common cause of fatality.

These results, published in Nature Immunology, highlight beta-glucan as a promising therapy for influenza and other emerging viral pathogens, said the scientists, adding future research will explore whether the findings can be applied to humans.

“It is remarkable how beta-glucan can reprogram certain immune cells, such as neutrophils, to control excessive inflammation in the lung,” said first author Nargis Khan, who conducted this research as a postdoctoral fellow at McGill and is now an Assistant Professor at the University of Calgary.

“Neutrophils are traditionally known for causing inflammation, but beta-glucan has the ability to shift their role to reduce it,” added co-first author Kim Tran, who recently completed her Ph.D. at McGill.

Rebalancing the immune system

Most flu-related deaths aren’t caused by the virus itself, but by an overreaction of the immune system, said the researchers. This suggests the true danger lies in the host’s own immune response. However, how the immune system becomes so imbalanced remains poorly understood.

“Beta-glucan is found in the cell walls of all fungi, including some that live in and on our bodies as part of the human microbiome,” explained Divangahi. “It is tempting to hypothesize that the levels and composition of fungi in an individual could influence how their immune system responds to infections, in part because of beta-glucan.”

With flu season underway and the looming threat of bird flu (H5N1), developing effective therapeutic strategies for respiratory diseases is more critical than ever, he added.

Reference: “Author Correction: β-Glucan reprograms neutrophils to promote disease tolerance against influenza A virus” by Nargis Khan, Kim A. Tran, Raphael Chevre, Veronica Locher, Mathis Richter, Sarah Sun, Mina Sadeghi, Erwan Pernet, Andrea Herrero-Cervera, Alexandre Grant, Ahmed Saif, Jeffrey Downey, Eva Kaufmann, Shabaana Abdul Khader, Philippe Joubert, Luis B. Barreiro, Bryan G. Yipp, Oliver Soehnlein and Maziar Divangahi, 7 February 2025, Nature Immunology.
DOI: 10.1038/s41590-025-02099-6

The research was funded by the Canadian Institutes of Health Research.