Probiotics for ear infections? Researchers demonstrate microbiota linked to ear health

09-Nov-2021 - Last updated on 09-Nov-2021 at 17:30 GMT

Getty Images / Marco VDM

Ear infections are typically treated with antibiotics, which could compromise the gut microbiome and reduce the ability of immune cells to kill bacteria. Now, fresh research indicates there could be a promising new approach to this relatively common childhood problem.

Growing research suggests there is a possible link between a probiotic bacteria and the prevention of ear infections. The latest research to delve into this area is a study published in Microbiology Spectrum, which examined the nasal microbiota in relation to inflammation of the middle ear (otitis media) in Indigenous Australian children.

Background

The authors pointed out that recurring and chronic ear infections are disproportionately prevalent in disadvantaged communities across the globe and within Indigenous communities in particular. In disadvantaged communities, this type of hearing loss is associated with negative educational and social development outcomes, and consequently, poorer employment prospects and increased contact with the justice system in adulthood. With all this in mind, the researchers hoped to gain a better understanding of the microbial ecology needed to identify new targets to treat and prevent ear infections.

The researchers, from the University of Queensland, previously used culturomics and species-specific quantitative to explore the nasal microbiota in relation to ear health and otitis media (OM) in 103 Indigenous Australian children. They found that children with historical or current OM/upper respiratory tract (URT) infection had large otopathogen loads and higher rates of detection of rhinovirus. In contrast, Corynebacterium pseudodiphtheriticum and Dolosigranulum pigrum were associated with upper respiratory tract and ear health. However, culture-based analyses can be insensitive to microbial population structure or unculturable organisms. To address this limitation, the researchers used 16S rRNA NGS along with the existing culturomics data to investigate the broader bacterial microbiome and how it relates to ear and nose health and disease in Indigenous Australian children.

The study

The research investigated the microbiomes of 103 children aged two to seven from two north Queensland communities. Two children refused swabbing, resulting in 101 swabs for analysis.

Findings

The researchers demonstrated that the nasal microbiota of Indigenous Australian children was related to ear and nose health.

"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,” said author Seweryn Bialasiewicz, PhD, a translational microbiologist and Senior Research Scientist at the Queensland Paediatric Infectious Diseases Laboratory. "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.”

Key takeaways

Healthy children with no history of OM showed a relationship between Dolosigranulum and Corynebacterium bacteria.
The researchers detected Ornithobacterium in children with OM, suggesting a potential role as a novel otopathogen in this population.
In relation to OM status, Moraxella had a greater relative abundance in children with a history of OM, compared to children with no history of OM, despite both groups having healthy ears at the time of swabbing.
In children with healthy noses, there was a negative correlation between Moraxella and Staphylococcus.
Correlations exist between C. pseudodiphtheriticum and D. pigrum in healthy children with no rhinorrhea and no historical OM.

Bialasiewicz said they hope to use this information to find the mechanism of protection and then replicate it to support or prevent OM in 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," Bialasiewicz explained.

Source: Microbiology Spectrum
Vol. 9, No. 2 doi.org/10.1128/Spectrum.00367-21
“Upper Respiratory Tract Microbiome of Australian Aboriginal and Torres Strait Islander Children in Ear and Nose Health and Disease”
Authors: A. Coleman et al.