Friendly bacteria reduces flu symptoms and ear infections in mice

A The Kids Research Institute Australia study has found that intranasal delivery of a friendly bacteria in mice reduced influenza symptoms and flu-driven ear infections, helping researchers move towards human studies.

The study tested effects of the Haemophilus haemolyticus bacteria in mice to uncover clues that could eventually lead to therapies to reduce flu severity and prevention of viral-driven bacterial middle ear infections, known as otitis media.

Despite vaccines being available, the flu and otitis media are still leading causes of illness and hospitalisation with recurrent ear infections leading to antibiotics and often grommet surgery.

The research, published today in The Journal of Infectious Diseases, found mice treated intranasally with friendly bacteria Haemophilus haemolyticus once a day for three days, recovered from the flu faster and had less virus and inflammation in the lungs when compared to placebo-treated mice.

Treated mice were also protected from developing otitis media when challenged with the pathogen responsible for most recurring and chronic ear infections.

Lead author Dr Naomi Scott, from the Wesfarmers Centre of Vaccines and Infectious Diseases at The Kids Research Institute Australia, said the study built on the team’s previous research which suggested that Haemophilus haemolyticus can be exploited for protection against respiratory infections.

“The friendly bacteria were well tolerated and effective as a nasal therapy in the mice, building on our previous findings in cell lines,” Dr Scott said.

“We can now start looking into further studies to deem whether these findings can transfer from mice to humans.”

Infectious disease microbiologist and co-author Associate Professor Lea-Ann Kirkham, from the Wesfarmers Centre of Vaccines and Infectious Diseases at The Kids Research Institute Australia and The University of Western Australia’s Centre for Child Health Research, said the prospect of a nasal therapy to reduce influenza severity and prevent development of otitis media could ease pressure on health care systems and decrease antibiotic use.

“Nasal therapies to prevent or treat respiratory infections hold so much promise as they can act directly at the site of infection,” Associate Professor Kirkham said.

“Parents and health-care workers alike have told us that they would love to have a therapy like this, especially if it means less ear infections and less antibiotics for children.”

The study Nasal delivery of Haemophilus haemolyticus is safe, reduces influenza severity, and prevents development of otitis media in mice is available here.

**This study was funded by research grants from the Wesfarmers Centre of Vaccines and Infectious Diseases, The Kids Research Institute Australia, Western Australian Dept. of Health Child Health Research Fund and Channel 7’s Telethon Trust**