Microbiome in Ear May Play Role in Ear Infections

Most commonly thought of in terms of the human gut, microbiomes, ear microbiomes in particular, may be the missing piece in the puzzling question of why some children suffer from more ear infections than others.

Microbiomes are made up of “helpful” bacteria that live with us and within us. The gut microbiome is most commonly associated with health; however, researchers have recently discovered that, “the human middle ear is inhabited by more diverse microbial communities than was previously thought. [Therefore,] alteration of the middle ear microbiome may contribute to the [cause] of chronic otitis media with active inflammation,” according to a new study presented at the American Academy of Otolaryngology—Head and Neck Surgery this past week in Chicago, Illinois.

For the study, Japanese researchers led by Shujiro Minami, MD, of the National Institute of Sensory Organs in Tokyo, Japan, set out to determine what role, if any, the microbiome in the ear might play in ear infections. As such, the researchers, “took swab samples of the middle ears of 155 children and adults who were having ear surgery due to recurrent ear infections (88 cases) or some other condition,” according to a press release on the study. An analysis of the samples revealed that significant differences existed in the microbiome for those with active (“wet) or inactive (“dry”) inflammation. Those individuals with inactive inflammation, in fact, “had similar middle ear microbiomes as the normal [no ear infection] middle ears group,” according to the researchers. Conversely, those with active inflammation had vastly different bacterial communities in their microbiome.

These results bring to light new information, but also more questions about the role of the ear’s microbiome in infections. “Are specific bacteria causing wet, dry, or active inflammation? Or are different people genetically predisposed to be 'wet' with chronic ear infections, which then allows certain kinds of bacteria to grow in the middle ear? Unfortunately, we still have a lot to learn." stated Sophia Jan, MD, chief of pediatrics at Cohen Children's Medical Center in New Hyde Park, New York, in the press release.