Gut bacteria can be a powerful ally in the fight against deadly secondary pneumonia following influenza, according to a groundbreaking study. The research, published in the journal Science Immunology, reveals that specific gut bacteria can significantly reduce the risk of this life-threatening complication. But here's where it gets controversial: the study also suggests that an individual's gut microbiota composition may be a key factor in determining who survives influenza pandemics.
The study focused on segmented filamentous bacteria (SFB), which are commonly found in the intestines of mammals. It examined whether SFB could influence the susceptibility of mice to secondary bacterial infections following influenza A virus infection. The researchers found that SFB provided marked protection against these highly lethal infections, which are often the cause of much of the morbidity and mortality associated with influenza pandemics.
The protection was mediated by specialized immune cells called alveolar macrophages, which are known to become dysfunctional following influenza viral infection. SFB, which resides exclusively on the outer surface of the intestine, epigenetically reprogrammed these macrophages to resist influenza virus-induced dysfunction, thus maintaining their robust defense against respiratory bacterial pathogens.
"The intestine is normally colonized by thousands of different bacterial species, but adding one more completely changes the way that lung macrophages respond to pathogens," said lead author Vu Ngo, a research assistant professor at the Institute for Biomedical Sciences at Georgia State.
This discovery opens up exciting possibilities for new pharmacologic approaches to mitigate the severity of respiratory infections. "We're very hopeful that we'll soon be able to harness the mechanism by which SFB reprograms alveolar macrophages, yielding novel pharmacologic approaches to mitigate the severity of a broad assortment of respiratory infections," added senior author Andrew T. Gewirtz.
The study was funded by the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health (NIH). It was authored by a team of researchers from the Institute for Biomedical Sciences at Georgia State, including Carolin M. Lieber, Hirohito Abo, Michal Kuczma, Jun Zou, and Richard K. Plemper.
This research not only highlights the potential of gut bacteria in combating secondary bacterial infections but also raises important questions about the role of gut microbiota in influenza survival. It invites further exploration and discussion on the potential of gut bacteria as a therapeutic target for respiratory infections.
