小児中耳炎におけるバイオフィルム形成とその微生物叢との関連性

Otitis media is among the most common pediatric illnesses globally, constituting a leading cause of antimicrobial prescriptions, recurrent medical consultations, and preventable hearing loss in early childhood. Traditionally regarded as a sterile cavity intermittently invaded by pathogens, the middle ear is now recognized as a dynamic ecological niche influenced by anatomical immaturity of the Eustachian tube, host immune development, and the composition of resident microbial communities. Increasing evidence demonstrates that microbial dysbiosis and the establishment of biofilms are central to the persistence and recurrence of disease. This review synthesizes current knowledge of the pediatric middle ear microbiome, highlighting how commensal organisms contribute to mucosal resilience and colonization resistance, whereas pathogenic bacteria exploit ecological disruption to establish biofilm communities. Biofilm formation provides bacteria with enhanced survival through immune evasion, altered microenvironments, and antibiotic tolerance, thereby transforming acute otitis media into recurrent or chronic states. Furthermore, studies demonstrate how adenoids act as reservoirs of biofilm-forming organisms, seeding the middle ear and perpetuating infection. The emerging ecological perspective emphasizes the limitations of conventional antibiotic-centered management and directs attention toward innovative strategies, including microbiome-preserving interventions, probiotic or live biotherapeutic approaches, and antibiofilm agents. By defining pediatric otitis media as a disorder of disrupted host-microbe equilibrium, future research may pave the way for precision-based preventive and therapeutic strategies aimed at reducing the global burden of this pervasive disease.