Middle Ear Infection

A measurable bacterial signature

Middle ear infections, known medically as otitis media, are one of the most common reasons young children see a doctor, affecting around half of children by age two. Researchers studying 163 infants, comparing those with an active ear infection to healthy infants, identified 58 different bacterial families in the nose and throat. Three families, Moraxellaceae, Streptococcaceae, and Pasteurellaceae, were the most common overall, and these contain the main bacteria known to cause ear infections. Infants with an active infection had noticeably fewer of the everyday, harmless bacteria that normally live there, making room for these infection-causing bacteria to take hold. Recent antibiotic use made this pattern more pronounced, further reducing the harmless bacteria that would otherwise help keep infection-causing species in check.

Source: Nasopharyngeal microbiota in infants with acute otitis media

The pattern shows up before the first infection

Some children get ear infections again and again. Researchers studying infants who went on to become "otitis-prone", meaning they had repeated, medically confirmed infections, found their nose and throat bacteria already looked different at just 6 months old, before their first infection had even happened. Four specific bacteria groups, Bacillus, Veillonella, Gemella, and Prevotella, were present at lower levels in these infants, and this held true even though the samples were collected while the infants were completely healthy, months before any diagnosis. Researchers found these same bacteria are linked to specific inflammatory signals, and their absence corresponded with a lower level of protective inflammation in the nose and throat, potentially leaving the area more vulnerable to infection when a virus or bacteria arrives.

Source: Nasopharyngeal microbiome analyses in otitis-prone and otitis-free children

Combining probiotics with treatment helps too

Chronic inflammation is a known driver of ear infections, and researchers reviewing the wider evidence on gut bacteria and hearing found that gut microbes influence inflammatory pathways that extend to the structures involved in hearing. For infections specifically, combining probiotics with a reduced dose of antibiotics produced better outcomes in some studies than aggressive antibiotics alone. It's worth remembering that a probiotic only introduces bacteria, it doesn't guarantee they'll survive. Like adding new animals to a zoo, they need an ongoing food source, fibre and plant compounds, to actually establish themselves rather than dying back out.

Source: PMC, Modulation of Gut Microbiome as a Therapeutic Modality for Auditory Disorders

What's actually inside the infected ear

Most research relies on nose and throat swabs, since these are easier to collect than fluid from inside the ear itself. One Swiss study went further, analysing 286 nasopharyngeal swabs from children with ear infections, and, in 42 of those children whose eardrum had already ruptured, the fluid from inside the middle ear too. The bacterial community inside the middle ear didn't always match what was found in the nose and throat, and the relationship between the two changed depending on the child's age, suggesting the bacteria that actually cause the infection can behave differently once they reach the ear itself.

Source: Age-Dependent Dissimilarity of the Nasopharyngeal and Middle Ear Microbiota in Children With Acute Otitis Media

What this means for you

Ear infections need proper diagnosis, and antibiotics remain the standard, appropriate treatment when a doctor prescribes them, especially since overusing them can further disrupt the protective bacteria discussed above. For children who get frequent infections, it's worth asking a doctor whether a probiotic strain alongside treatment is appropriate, given the evidence above. That's the same idea behind GutLab, everyday gut health starts with regularly feeding the microbiome a broad range of plant-rich ingredients.