According to a new study, a component found in all mushrooms could offer protection against lung damage caused by the flu.
A team of scientists led by Maziar Divangahi, a professor at McGill University's Faculty of Medicine and Health Sciences and senior scientist at the Research Institute of the McGill University Health Centre, revealed that administering beta-glucan to mice before their exposure to the flu could reduce lung damage, improve respiratory function, and decrease the risks of illness and death.
Beta-glucan is a component of all mushrooms, including yeasts, as well as certain cereals such as oats and barley. Scientists discovered that a unique structure of this component could strengthen defense against pathogens.
Unlike most studies, which aim to prevent virus replication, this one explored the regulation of the body's immune response to infection, a concept called "disease tolerance." The research team found that beta-glucan significantly improved flu survival rates by modulating immune responses and preventing severe lung inflammation, a common cause of mortality.
The scientists indicated that their results, published in the journal Nature Immunology, suggest that beta-glucan could be a promising treatment for the flu and other emerging pathogens. They added that future research will determine whether these findings can be applied to humans.
"Beta-glucan can reprogram certain immune cells, including neutrophils, to reduce excessive lung inflammation, which is remarkable," said lead author Nargis Khan, who conducted this research as a postdoctoral fellow at McGill University and now holds an assistant professorship at the University of Calgary.
"We know that neutrophils are responsible for inflammation—and beta-glucan can reprogram neutrophils to reduce inflammation rather than cause it," added co-lead author Kim Tran, who recently earned her PhD at McGill University.
A rebalancing of the immune system According to the research team, most flu-related deaths are not caused by the virus itself but by an overreaction of the immune system. The real danger, therefore, comes from the infected person's immune response. The source of this immune system imbalance, however, is still not well understood.
"Beta-glucan is found in the cell walls of all fungi, including those that live in and on our bodies and are part of the human microbiome," explained Professor Divangahi. "It is tempting to hypothesize that the quantity and composition of fungi present in a person would influence their immune system's response to infections, partly thanks to beta-glucan."
"Flu season has begun, and the threat of avian flu (H5N1) looms," he added. "It is therefore more important than ever to develop effective therapeutic strategies for respiratory diseases."
This research was funded by the Canadian Institutes of Health Research.
Reference:
The article "β-Glucan reprograms neutrophils to promote disease tolerance against influenza A virus," by Nargis Khan, Kim Tran, Maziar Divangahi, et al., was published in the journal Nature Immunology.