Bacteria in children's microbiomes could defend against certain types of hearing loss

Studying microbes found in the upper respiratory tracts of disease-resistant kids may lead to the development of treatments for chronic ear disease.

Published: November 9, 2021 at 4:31 pm

Chronic middle ear infections can affect between one-third and one-half of Aboriginal and Torres Strait Islander children, specialists in Australia say. The disease can lead to life-long impacts on hearing and speech that can have far-reaching consequences on education and future employment prospects.

However, researchers have been unable to pin down exactly why some children never go on to develop the disease while their friends and neighbours do.

Now, a team based at the University of Queensland think they may have the answer: the disease-resistant kids have colonies of bacteria in their respiratory systems that provide them with protection from infection.

The team studied the microbiomes of 103 children aged between two and seven from two north Queensland communities using nasal swab samples, and also examined their ears, noses and throats.

They found that the children who had the microbes Dolosigranulum andCorynebacterium present in their microbiomes were more likely to have better upper respiratory tract and ear health.

“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,” said Dr Seweryn Bialasiewicz.

“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.”

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The team now plan to study the effect further to figure out what the exact mechanism of protection is, and then apply it as a therapy or a preventative measure in very young children.

“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,” he said.

As chronic middle ear infections resulting in hearing loss are a major problem with other disadvantaged populations across the world, any treatments developed could also be rolled out globally, the researchers say.

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