Writing in Frontiers in Immunology, scientists from the French National Institute of Health and Medical Research (Inserm) reported that supplementation with F. duncaniae (formerly referred to as F. prausnitzii) led to less severe disease, a lower pulmonary viral load and lower levels of lung inflammation, compared to the control group.
In addition, the data showed that the live bacteria (probiotic) was more potent than the pasteurized form (postbiotic) for improving the outcomes associated with flu.
“Our present results suggest that F. duncaniae—a major, canonical, butyrate-producing human commensal—might serve as a novel next generation probiotic against viral respiratory diseases,” they wrote.
Probiotics and the flu
The study adds to a growing body of science supporting probiotic supplementation and improved outcomes relating to respiratory tract infections.
Indeed, a 2019 paper published in Frontiers in Pharmacology indicated that probiotics may reduce the duration of flu-like respiratory tract infection, the use of antibiotics and missed days at work, all of which would translate into over $1 billion of costs savings in the United States.
5–20% of the population will have at least one RTI every year
In the US, this leads to:
31.4 million outpatient visits,
3.1 million hospitalized days,
41,000 deaths every year.
Study details
For the new study, the Inserm scientists divided lab mice into five groups: One group received no intervention, one group was infected with influenza A but no other intervention, and the three other groups received supplements of live F. duncaniae (A2-165 or I-4574 strains) or pasteurized A2-165 for five days before infection with influenza A.
Results showed that both live strains were associated with partial protection against flu, with less body weight loss, a lower viral load in the lungs, and lower levels of pulmonary and gut inflammation, the researchers reported.
The live form performed significantly better than the pasteurized form.
“It is important to note that supplementation with F. duncaniae also alleviated systemic secondary bacterial infections,” they added. “These protective effects were associated with a change in gut microbiota composition and an augmentation of SCFA [short chain fatty acid] levels in diseased animals.
“We conclude that F. duncaniae might serve as a novel next generation probiotic against acute viral respiratory diseases.”
Source: Frontiers in Immunology
2024, Volume 15, doi: 10.3389/fimmu.2024.1347676
“Faecalibacterium duncaniae as a novel next generation probiotic against influenza”
Authors: L. Chollet, et al.