The good bact-ear-ia

Good bacteria in the upper respiratory systems of children could help fight chronic middle ear infections, the leading cause of preventable hearing loss and deafness in Indigenous communities, according to a new study published in Microbiology Spectrum.

“Chronic middle ear infections can affect between one third to one half of Aboriginal and Torres Strait Islander children, which is far above the 4% threshold that the World Health Organization considers as a disease needing urgent public health action,” says Dr Andrea Coleman of the University of Queensland, who was part of the project.

“This disease can cause hearing loss and can have lifelong impacts on speech and language development, education and future employment prospects, and in Aboriginal and Torres Strait Islander populations contributes to the wide gap in educational and employment outcomes.”

The study investigated 103 Indigenous children between the ages of two and seven from two communities in north Queensland. By taking nasal swabs and assessing the children’s microbiomes, the researchers found that children who had never had middle ear infection had higher abundance of two biota: Dolosigranulum and Corynebacterium.

The also found a high abundance of Moraxella in children who had a history of middle ear infection but had healthy ears.

“We’ve been puzzled for years now, trying to work out why some children never develop chronic ear disease, despite being in a high-risk category for contracting it,” says Dr Seweryn Bialasiewicz of the University of Queensland, who was involved in the project.

“By focusing on the microbiomes in the upper respiratory tracts of disease-resistant kids, we could investigate the ecological networks of bacterial interactions that seemed to be working together to protect against the condition.

“It was clear that these two groups of bacteria needed to not only be present, but to be interacting with each other, to provide protection from middle ear infections.”

The team hopes that these microbiota could be utilised to prevent hearing loss due to chronic ear infection.

“This could take the form of a molecule that can be used as a drug for treatment, or as a protective probiotic so that these ‘good’ bacteria can be seeded in the nose early enough to offer protection against the incoming ‘bad’ bacteria,” says Bialasiewicz.

“Our discovery could be applied across the world, helping improve health and reducing the disadvantage gap for a wide range of people.”

The team has acknowledged the support of the Deadly Ears team – Queensland Health’s statewide Aboriginal and Torres Strait Islander Ear Health Program doing on-the-ground treatment and education – as well as the generous assistance of parents and children within the participating communities.