CHICAGO, Jan. 12 (Xinhua) -- Researchers at the University of Michigan (UM) have identified a cluster of nose and throat bacteria that made their hosts less likely to get the flu.

The researchers have used data from a longitudinal household transmission study of influenza to evaluate the relationship between nose/throat bacteria and the host's susceptibility to the influenza virus.

The participants were enrolled in the Nicaraguan Household Transmission Study during 2012-2014. Household members of individuals with confirmed influenza were recruited for the study and followed for 13 days or until they developed influenza, whichever came first. Of the study's 717 enrollees from 144 households, the analysis included only the 537 individuals who tested negative for influenza at the beginning of the study.

The researchers looked at samples of nose and throat bacteria collected at the time of enrollment and used DNA sequencing to identify which bacteria were present. When analyzing the bacterial composition across all samples, they found five clusters.

After taking into account other known factors that could affect an individual's susceptibility to influenza, such as age, exposure to tobacco, crowded household and flu vaccination, the researchers then looked to see if individuals with a given cluster were less likely to get influenza.

"We looked at who had which cluster and whether it makes a difference on whether they got influenza, and it does," said lead author Betsy Foxman, a professor of epidemiology at the UM School of Public Health. "That's the exciting thing about it. It tells us if you have this bacterial community, you have lower risk for getting the flu. That's big news because it really hasn't been shown before."

This also brings new questions.

"Is it really possible to push someone's microbiome in a way that would make a difference? Is it possible that we could tell people, 'Here's your microbiome pill?' " Foxman said. "It's a very long road and we're at the beginning."

In the next step, the researchers hope similar studies can be done in a different population and possibly follow them longer for secondary bacterial infections.

"We know we are always going to need new antibiotics, but this way we could hold on to them longer and, presumably, if we could intervene in this way there would be fewer side effects," Foxman said.

The study was published Wednesday on UM website.