Microbes could help protect kids’ hearing

Bacteria found in children’s upper respiratory tracts may help fight chronic middle ear infections, a new study found.


Middle ear infections are the leading cause of preventable hearing loss and deafness in Indigenous communities. Now, a new study found that bacteria living in the upper respiratory system may help fight off these infections.

The study, led by Dr Seweryn Bialasiewicz, from the University of Queensland, may explain the long-held conundrum of why some high-risk children never develop chronic ear disease. The key may be in their microbes.

“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,” Dr Bialasiewicz said.

“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,” she added.

About the study
The new study analysed the nasal microbiota of 103 Indigenous Australian children 2 to 7 years of age from two northern Queensland communities, including 17 healthy children used as controls. Using next-generation DNA sequencing technology, researchers identified the bacterial groups that made up the nasal microbiota of these children.

Their results showed that the microbiota of healthy children differed from that of children with ear conditions. For example, children with historical Otitis Media had greater relative abundance of bacteria of the genus Moraxella, compared to healthy children. In contrast, children with healthy noses had greater relative abundance of the Staphylococcus aureus bacterium, compared to children suffering from rhinorrhea. Other groups of bacteria, like Ornithobacterium, were found to be absent in healthy children and found in abundance around other ear pathogens in children with an ear condition.

According to Dr Andrea Coleman, who completed her PhD work as part of this study, their findings provide a new perspective on how middle ear infections develop and could pave the way for new treatments.

“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,” Dr Bialasiewicz said.

The development of new treatments for chronic middle ear infections is sorely needed, particularly for children from Indigenous communities. “Chronic middle ear infections can affect between one third to one half of Aboriginal and Torres Strait Islander children, which is far above the four per cent threshold that the World Health Organisation considers as a disease needing urgent public health action,” Dr Coleman said.

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