{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,23]],"date-time":"2026-07-23T17:01:23Z","timestamp":1784826083084,"version":"3.55.0"},"reference-count":38,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T00:00:00Z","timestamp":1773360000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Riga Stradi\u0146\u0161 university"},{"name":"Strengthening of the capacity of doctoral studies at the University of Latvia within the framework of the new doctoral model","award":["8.2.2.0\/20\/I\/006"],"award-info":[{"award-number":["8.2.2.0\/20\/I\/006"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>Background: The adenoid surface serves as a potential bacterial reservoir for upper respiratory tract pathologies, including Adenoid Hypertrophy (AH) and Otitis Media with Effusion (OME). While dysbiosis is implicated in the pathogenesis of these conditions, it remains unclear whether the microbiome of children with otitis media differs significantly from those with simple hypertrophy when compared against a healthy baseline. This study aimed to characterize the adenoid microbiome in children with adenoid hypertrophy with and without middle ear effusion, contrasting them with a healthy control group. Methods: We conducted a cross-sectional case\u2013control study involving 58 pediatric participants divided into three groups: adenoid hypertrophy, adenoid hypertrophy and otitis media with effusion and healthy controls. Nasopharyngeal swabs were collected, and bacterial community composition was analyzed using 16S rRNA gene V4 sequencing. Alpha and beta diversity metrics, taxonomic composition, and differential abundance were evaluated. Results: Alpha diversity was significantly reduced in both disease groups compared to healthy controls (p &lt; 0.001), indicating a collapse of microbial richness and evenness. Beta diversity analysis revealed a distinct separation between healthy and diseased cohorts; however, the microbial profiles of the AH and AH with OME groups were nearly identical. Taxonomic analysis demonstrated that disease was characterized by the depletion of health-associated commensals, specifically Veillonella, Actinomyces, and Gemella, and a concomitant expansion of Fusobacterium, Haemophilus, and Streptococcus. Conclusions: Adenoid hypertrophy is associated with a profound dysbiotic shift characterized by the loss of protective commensal flora and the dominance of pathobionts. The lack of significant microbial differentiation between the AH and AH with OME groups suggests that the adenoid surface acts as a centralized reservoir of dysbiosis, the composition of which is conserved regardless of the presence of middle ear effusion. These findings highlight the importance of restoring the commensal microbiome in the management of chronic adenoid disease.<\/jats:p>","DOI":"10.3390\/jcm15062187","type":"journal-article","created":{"date-parts":[[2026,3,13]],"date-time":"2026-03-13T09:26:38Z","timestamp":1773393998000},"page":"2187","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["The Clinical Role of the Adenoid Microbiome in the Development of Adenoid Hypertrophy and Otitis Media with Effusion"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7146-1803","authenticated-orcid":false,"given":"O\u013cegs","family":"Sokolovs-Karijs","sequence":"first","affiliation":[{"name":"Department of Otolaryngology, Riga Stradi\u0146\u0161 University, 16 Dzirciema Str., LV-1007 Riga, Latvia"},{"name":"AIWA Clinic, 241 Latgales Str., LV-1019 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Monta","family":"Br\u012bv\u012bba","sequence":"additional","affiliation":[{"name":"Latvian Biomedical Research and Study Centre, 1 Ratsupites Str., LV-1067 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9446-4521","authenticated-orcid":false,"given":"Dita","family":"Gudr\u0101","sequence":"additional","affiliation":[{"name":"Latvian Biomedical Research and Study Centre, 1 Ratsupites Str., LV-1067 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0002-5017-5688","authenticated-orcid":false,"given":"Rihards","family":"Saksis","sequence":"additional","affiliation":[{"name":"Latvian Biomedical Research and Study Centre, 1 Ratsupites Str., LV-1067 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Annija Alise","family":"Zod\u0101ne","sequence":"additional","affiliation":[{"name":"Latvian Biomedical Research and Study Centre, 1 Ratsupites Str., LV-1067 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-7735-682X","authenticated-orcid":false,"given":"Maija","family":"Rozenberga","sequence":"additional","affiliation":[{"name":"Latvian Biomedical Research and Study Centre, 1 Ratsupites Str., LV-1067 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laura","family":"Bunka","sequence":"additional","affiliation":[{"name":"Latvian Biomedical Research and Study Centre, 1 Ratsupites Str., LV-1067 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna","family":"Frigotto","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Riga Stradi\u0146\u0161 University, 16 Dzirciema Str., LV-1007 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jana","family":"Os\u012bte","sequence":"additional","affiliation":[{"name":"Centr\u0101l\u0101 Laboratorija, 4a Gr\u0113du Str. LV-1019 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3671-1213","authenticated-orcid":false,"given":"Aigars","family":"Reinis","sequence":"additional","affiliation":[{"name":"Department of Biology and Microbiology, Riga Stradi\u0146\u0161 University, 16 Dzirciema Str., LV-1007 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gunta","family":"Segli\u0146a","sequence":"additional","affiliation":[{"name":"Department of Otolaryngology, Riga Stradi\u0146\u0161 University, 16 Dzirciema Str., LV-1007 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Angelika","family":"Kr\u016bmi\u0146a","sequence":"additional","affiliation":[{"name":"Department of Infectology, Riga Stradi\u0146\u0161 University, 16 Dzirciema Str., LV-1007 Riga, Latvia"},{"name":"Institute of Food Safety, Animal Health and Environment BIOR, 3 Lejupes Str., LV-1076 Riga, Latvia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3705","DOI":"10.1002\/1873-3468.12455","article-title":"Composition and immunological significance of the upper respiratory tract microbiota","volume":"590","author":"Schenck","year":"2016","journal-title":"FEBS Lett."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1111\/imm.13195","article-title":"Respiratory microbiome and epithelial interactions shape immunity in the lungs","volume":"160","author":"Invernizzi","year":"2020","journal-title":"Immunology"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"704","DOI":"10.1016\/j.chom.2015.03.008","article-title":"The Infant Nasopharyngeal Microbiome Impacts Severity of Lower Respiratory Infection and Risk of Asthma Development","volume":"17","author":"Teo","year":"2015","journal-title":"Cell Host Microbe"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"e001710","DOI":"10.1136\/bmjpo-2022-001710","article-title":"Adenoid hypertrophy in children: A narrative review of pathogenesis and clinical relevance","volume":"7","author":"Niedzielski","year":"2023","journal-title":"BMJ Paediatr. 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