United States: A new study conducted today (November 20) as a journal of the American Society for Microbiological Society’s mSystems shows that cigarettes have an effect in altering the oropharyngeal microbiota leading to increased severity of influenza A virus infections.
Cigarette smoking is well understood to be unhealthy, and has been linked to specific respiratory diseases such as pulmonary diseases and a higher susceptibility to flu. However, the changes to the composition of the microbiota in the oropharynx caused by cigarette smoke were not publicized until recent years. However, until the present study, the extent to which such disruption influences disease severity remained unclear, as reported by scitechdaily.com.
Microbiota Disruption by Smoking
The chronic cigarette exposure was also remarked to change the gut and oropharyngeal microbiota in mice according to a new study. To separate the impact of smoking and the altered microbiota, the researchers took the mice and treated them with cigarette smoke and cohoused them with mice treated with air (vehicle) and germ-free mice. This was made possible to facilitate the transfer of microbiota from donor mice to what was offered as germ-free mice. The original germ-free mice were colonized either with bacteria from a smoke exposed or air exposed mouse. The scientists then infected the recipient mice with influenza A virus and then evaluated their disease progression.
The investigators discovered that the first generation germ-free mice, which incorporated bacteria from smoke-exposed mice fare worse, in terms of weight lost, than the smoke only group. Furthermore, we noted the profound impact of virus infection on the composition of oropharyngeal microbiota, which reached significant changes starting from day 4 and even more on day 8 of the viral infection. The current study was structured in a way that separated the impact of the disturbed microbiota from real smoke immunomodulation, as reported by scitechdaily.com.
Research Findings and Implications
“It is not only the smoking per se that impacts respiratory disease, but our data indicate that the smoker’s microbiota may also impact respiratory disease and/or infection. In our case, it impacts viral infection,” said corresponding study author Markus Hilty, Ph.D., associate professor at the Institute for Infectious Diseases, University of Bern in Switzerland. “The cigarette-induced disordering of the microbiota is probably an important factor to consider during viral infection.”