Nasal microbial composition and chronic otitis media with effusion: A case-control study

[Current hypotheses on the development of chronic otitis media with effusion in childhood]

Chronic otitis media with effusion (COME) has a major impact on a child's physical and social development. Socioeconomic risk factors as well as new insights gained with modern laboratory technology and large demographic studies of COME in Central Europe are discussed. In total, 428 articles from the past 8 years on PubMed were reviewed as well as current guidelines of German- and English-speaking countries on COME in children. Problems of many original studies include small patient numbers and bias. In addition, a clear distinction between acute otitis media and COME is often missing. Microbiomic profiles and biofilms seem to play a major role in COME. Established theories on the multifactorial origin of COME are mostly supported by new studies, including new insights into immunological and nutritional risk factors. In addition, the socioeconomic background of a child with COME must not be underestimated, even in first-world countries.

Bacteriome of the Middle Ear in Children and Young Adults With Cholesteatoma and Retraction Pocket: A Pilot Study

Objective

Chronic otitis media (COM) is a common middle ear disease in children and young adults. Dysfunction of the Eustachian tube and bacterial infection are the main causes. This pilot study aimed to describe and compare bacteriomes of the middle ear in children and young adults with serious forms of COM, such as cholesteatoma and retraction pocket (RP) of the tympanic membrane, with bacteriomes in healthy middle ears.

Study Design

Observational study.

Setting

Clinical practice in a tertiary center. From January 1, 2021 to August 31, 2022. Patients aged 0 to 20 years.

Methods

In this case-control study, middle ears were swabbed during surgery on children with cholesteatoma (N = 23) or RP (N = 26) and on children indicated for cochlear implant (N = 15, controls). Genomic DNA extraction was followed by creation of a 16S ribosomal DNA gene library and sequencing on a MiSeq instrument. Samples with relative abundance of at least one bacterial genus >20% were considered positive for the specific genus.

Results

Bacterial diversity was generally low in the middle ear samples from patients with COM, with DNA content from 1 or 2 bacteria usually dominating in the sample. A significant difference in positivity for one or more bacterial genera was observed between patients with cholesteatoma or RP (38.8%) versus patients indicated for cochlear implants (6.7%).

Conclusion

While middle ear bacteriomes in cases of cholesteatoma and RP differed from those of controls, findings in the 2 pathological conditions were similar. These results support the statement that the RP could be a precholesteatoma stage.

Panel 1: Epidemiology and global health, including child development, sequelae and complications

OBJECTIVE

To summarise the published research evidence on the epidemiology of otitis media, including the risk factors and sequelae associated with this condition.

DATA SOURCES

Medline (PubMed), Embase, and the Cochrane Library covering the period from 2019 to June 1st, 2023.

REVIEW METHODS

We conducted a broad search strategy using otitis [Medical Subject Heading] combined with text words to identify relevant articles on the prevalence, incidence, risk factors, complications, and sequelae for acute otitis media, otitis media with effusion, and chronic suppurative otitis media. At least one review author independently screened titles and abstracts of the retrieved records for each condition to determine whether the research study was eligible for inclusion. Any discrepancies were resolved by reviewing the full text followed by discussion with a second review author. Studies with more than 100 participants were prioritised.

RESULTS

Over 2,000 papers on otitis media (OM) have been published since 2019. Our review has highlighted around 100 of these publications. While the amount of otitis media research on the Medline database published each year has not increased, there has been an increase in epidemiological studies using routinely collected data and systematic review methodology. Most of the large incidence studies have addressed acute otitis media (AOM) in children. Several studies have described a decrease in incidence of AOM after the introduction of conjugate PCV vaccines. Similarly, a decrease was noted when rates of coronavirus disease of 2019 (COVID-19) were high and there were major public health efforts to reduce the spread of infection. There have been new studies on OM in adults and OM prevalence in a broader range of countries and population subgroups.

CONCLUSION

Overall, the rates of severe and/or suppurative OM appeared to be decreasing. However, there is substantial heterogeneity between populations. While better use of available data is informative, it can be difficult to predict rates of severe disease without accurate examination findings. Most memorably, the COVID-19 pandemic had an enormous impact on the research and clinical services for otitis media for most of the period under review.

IMPLICATIONS FOR PRACTICE

The use of routinely collected data for epidemiological studies will lead to greater variability in the definitions and diagnostic criteria used. The impact of new vaccines will continue to be important. Some of the lessons learned during the COVID-19 pandemic concerning behaviours that reduce spread of respiratory viruses can hopefully be used to decrease the burden of otitis media in the future. There are still many countries in the world where the burden of otitis media is not well described. In countries where otitis media has been studied over many years, new potential risk factors continue to be identified. In addition, a better understanding of the disease in specific subgroups has been achieved.

Otitis Media in Children with Down Syndrome Is Associated with Shifts in the Nasopharyngeal and Middle Ear Microbiotas

Background: Otitis media (OM) is defined as middle ear (ME) inflammation that is usually due to infection. Globally, OM is a leading cause of hearing loss and is the most frequently diagnosed disease in young children. For OM, pediatric patients with Down syndrome (DS) demonstrate higher incidence rates, greater severity, and poorer outcomes. However, to date, no studies have investigated the bacterial profiles of children with DS and OM. Method: We aimed to determine if there are differences in composition of bacterial profiles or the relative abundance of individual taxa within the ME and nasopharyngeal (NP) microbiotas of pediatric OM patients with DS (n = 11) compared with those without DS (n = 84). We sequenced the 16S rRNA genes and analyzed the sequence data for diversity indices and relative abundance of individual taxa. Results: Individuals with DS demonstrated increased biodiversity in their ME and NP microbiotas. In children with OM, DS was associated with increased biodiversity and higher relative abundance of specific taxa in the ME. Conclusion: Our findings suggest that dysbioses in the NP of DS children contributes to their increased susceptibility to OM compared with controls. These findings suggest that DS influences regulation of the mucosal microbiota and contributes to OM pathology.

Altered Faecal Microbiota Composition and Structure of Ghanaian Children with Acute Gastroenteritis

Acute gastroenteritis (AGE) is a disease of global public health importance. Recent studies show that children with AGE have an altered gut microbiota relative to non-AGE controls. Yet, how the gut microbiota differs in Ghanaian children with and without AGE remains unclear. Here, we explore the 16S rRNA gene-based faecal microbiota profiles of Ghanaian children five years of age and younger, comprising 57 AGE cases and 50 healthy controls. We found that AGE cases were associated with lower microbial diversity and altered microbial sequence profiles relative to the controls. The faecal microbiota of AGE cases was enriched for disease-associated bacterial genera, including Enterococcus, Streptococcus, and Staphylococcus. In contrast, the faecal microbiota of controls was enriched for potentially beneficial genera, including Faecalibacterium, Prevotella, Ruminococcus, and Bacteroides. Lastly, distinct microbial correlation network characteristics were observed between AGE cases and controls, thereby supporting broad differences in faecal microbiota structure. Altogether, we show that the faecal microbiota of Ghanaian children with AGE differ from controls and are enriched for bacterial genera increasingly associated with diseases.

Analysis of factors that influence the occurrence of otitis media with effusion in pediatric patients with adenoid hypertrophy

Objective

Adenoid hypertrophy (AH) and otitis media with effusion (OME) are common pediatric otolaryngological diseases and often occur concurrently. The purpose of this study was to comprehensively analyze the factors that influence the occurrence of OME pediatric patients with AH.

Methods

Patients younger than 12 years with AH, who were hospitalized for treatment at Beijing Tsinghua Changgung Hospital in Beijing, China, between March 2018 and February 2022 were enrolled. The patients were divided into an AH group and an AH + OME group based on the presence of OME. The authors collected the following clinical data for univariable analysis: sex; age; body mass index (BMI); comorbid nasal congestion/rhinorrhea, recurrent tonsillitis, or allergic rhinitis (AR); adenoid and tonsil grade; tonsillar hypertrophy; food/drug allergy; history of adenoidectomy and congenital diseases; breastfeeding status; preterm birth; exposure to environmental tobacco smoke (ETS); family history of adenotonsillectomy, otitis media, and AR; main data of polysomnography and oropharyngeal conditional pathogen culture data of some patients. Univariate analysis was performed as a basis for logistic regression analysis.

Results

A total of 511 children (329 boys and 182 girls) were included, their mean age was 5.37 ± 2.10 years. Of them, 407 (79.6%) were in the AH group and 104 (20.4%) in the AH + OME group. Univariate analysis revealed statistically significant differences in age, BMI, adenoid grade, AR, breastfeeding status, and ETS exposure between the two groups. Multivariate stepwise logistic regression analysis showed that age, adenoid grade, AR, breastfeeding status, and ETS influenced the occurrence of OME in pediatric patients with AH. The risk of OME decreased with increasing age. High adenoid grade, ETS exposure, and comorbid AR were risk factors for OME in pediatric patients with AH, but breastfeeding was a protective factor. The final analytical results of the oropharyngeal conditional pathogen culture data showed that Streptococcus pneumoniae positivity was associated with OME in AH.

Conclusion

The pathogenesis of AH with OME is complex. Young age, high adenoid grade, ETS exposure, non-breastfed status, comorbid AR, and the presence of S. pneumoniae in the oropharynx are risk factors for OME in pediatric patients with AH.

Common and Rare Genetic Variants That Could Contribute to Severe Otitis Media in an Australian Aboriginal Population

BACKGROUND

Our goal was to identify genetic risk factors for severe otitis media (OM) in Aboriginal Australians.

METHODS

Illumina® Omni2.5 BeadChip and imputed data were compared between 21 children with severe OM (multiple episodes chronic suppurative OM and/or perforations or tympanic sclerosis) and 370 individuals without this phenotype, followed by FUnctional Mapping and Annotation (FUMA). Exome data filtered for common (EXaC_all ≥ 0.1) putative deleterious variants influencing protein coding (CADD-scaled scores ≥15] were used to compare 15 severe OM cases with 9 mild cases (single episode of acute OM recorded over ≥3 consecutive years). Rare (ExAC_all ≤ 0.01) such variants were filtered for those present only in severe OM. Enrichr was used to determine enrichment of genes contributing to pathways/processes relevant to OM.

RESULTS

FUMA analysis identified 2 plausible genetic risk loci for severe OM: NR3C1 (Pimputed_1000G = 3.62 × 10-6) encoding the glucocorticoid receptor, and NREP (Pimputed_1000G = 3.67 × 10-6) encoding neuronal regeneration-related protein. Exome analysis showed: (i) association of severe OM with variants influencing protein coding (CADD-scaled ≥ 15) in a gene-set (GRXCR1, CDH23, LRP2, FAT4, ARSA, EYA4) enriched for Mammalian Phenotype Level 4 abnormal hair cell stereociliary bundle morphology and related phenotypes; (ii) rare variants influencing protein coding only seen in severe OM provided gene-sets enriched for "abnormal ear" (LMNA, CDH23, LRP2, MYO7A, FGFR1), integrin interactions, transforming growth factor signaling, and cell projection phenotypes including hair cell stereociliary bundles and cilium assembly.

CONCLUSIONS

This study highlights interacting genes and pathways related to cilium structure and function that may contribute to extreme susceptibility to OM in Aboriginal Australian children.

Respiratory and Neurological Disease across Different Ethnic Groups Is Influenced by the Microbiome

Acute and chronic upper respiratory illnesses such as asthma, and allergic rhinitis (AR) have been linked to the presence of microorganisms in the nose. Microorganisms can exist in symbiotic or commensal relationships with the human body. However, in certain cases, opportunistic pathogens can take over, leading to altered states (dysbiosis) and causing disease. Thus, the microflora present in a host can be useful to reflect health status. The human body contains 10 trillion to 100 trillion microorganisms. Of these populations, certain pathogens have been identified to promote or undermine wellbeing. Therefore, knowledge of the microbiome is potentially helpful as a diagnostic tool for many diseases. Variations have been recognized in the types of microbes that inhabit various populations based on geography, diet, and lifestyle choices and various microbiota have been shown to modulate immune responses in allergic disease. Interestingly, the diseases affected by these changes are prevalent in certain racial or ethnic populations. These prevalent microbiome variations in these groups suggest that the presence of these microorganisms may be significantly associated with health disparities. We review current research in the search for correlations between ethnic diversity, microbiome communities in the nasal cavity and health outcomes in neurological and respiratory functions.

Effects of the Traditional Mediterranean Diet in Patients with Otitis Media with Effusion

INTRODUCTION

Otitis media with effusion (OME) is common in pediatric primary care consultations. Its etiology is multifactorial, although it has been proven that inflammation factors mediate and that immunity is in a phase of relative immaturity. The objective of this study was to assess the effects of the Traditional Mediterranean Diet (TMD) modulating inflammation and immunity in patients diagnosed with OME.

MATERIALS AND METHODS

A analysis as a single-group pre-test/post-test was conducted on 40 girls and 40 boys between 18 months and 5 years old. Tympanometry normalization was the main test to control the benefit of diet. Clinical and therapeutic variables were studied through evaluation questionnaires, a quality test of the diet, as well as various anthropometric parameters.

RESULTS

At the end of one year, tympanometry had normalized in 85% of patients. The remaining 15% had normal audiometry and/or associated symptoms had decreased. Likewise, episodes of recurrent colds decreased from 5.96 ± 1.41 to 2.55 ± 0.37; bacterial complications of 3.09 ± 0.75 to 0.61 ± 0.06 and persistent nasal obstruction of 1.92 ± 0.27 to 0.26 ± 0.05. The degree of satisfaction of the families with the program was very high.

CONCLUSIONS

The application of the Traditional Mediterranean Diet could have promising effects in the prevention and treatment of otitis media with effusion.

Tissue microbiota in nasopharyngeal adenoid and its association with pneumococcal carriage

The microbial colonization in the nasopharynx is a prerequisite for the onset of infectious diseases. For successful infection, pathogens should overcome host defenses as well as compete effectively with the resident microbiota. Hence, elucidating the richness and diversity of the microbiome at the site of pathogen colonization is pivotal. Here, we investigated the adenoidal tissue microbiota collected through adenoidectomy to evaluate the impact of Streptococcus pneumoniae. Prospectively, children with sleep-disordered breathing (SDB) and otitis media with effusion (OME) were enrolled. During adenoidectomy, the nasopharyngeal swab and adenoid tissues were collected to determine the pneumococcal carriage and tissue microbiota, using multiplex PCR and 16S ribosomal RNA (16S rRNA) pyrosequencing. A total of 66 pediatric patients comprising 38 children with SDB and 28 children with OME were enrolled. There was no difference between the bacterial cultures from the surface of the nasopharyngeal adenoid in the SDB and OME groups. Thirty-four samples (17 SDB and 17 OME) underwent 16S rRNA pyrosequencing and fulfilled the criteria for further analysis. The Shannon diversity index for the samples from the SDB patients was found to be higher than that observed for the samples from OME patients, although the difference was not significant (p = 0.095). The Shannon diversity index for the samples negative for the pneumococcal carriage was significantly higher than that for the samples positive for pneumococcal carriage (p = 0.038). Alloprevotella, Staphylococcus, Moraxella, and Neisseriaceae were significantly dominant in the samples positive for the pneumococcal carriage. Dialister was significantly less present in the adenoid tissue positive for the pneumococcal carriage. Streptococcus pneumoniae, one of the most common pathogens of the airway, significantly influences the composition and diversity of the microbiota in the nasopharyngeal adenoid. Thus, bacterial community analysis based on 16S rRNA pyrosequencing allows for better understanding of the relationship between the adenoidal microbial communities.

Case-Control Microbiome Study of Chronic Otitis Media with Effusion in Children Points at Streptococcus salivarius as a Pathobiont-Inhibiting Species

Chronic otitis media with effusion (OME) has been associated with a shift in microbiome composition and microbial interaction in the upper respiratory tract (URT). While most studies have focused on potential pathogens, this study aimed to find bacteria that could be protective against OME through a case-control microbiome study and characterization of isolates from healthy subjects. The URT and ear microbiome profiles of 70 chronic OME patients and 53 controls were compared by 16S rRNA amplicon sequencing. Haemophilus influenzae was the most frequent classic middle ear pathobiont. However, other taxa, especially Alloiococcus otitis, were also frequently detected in the ear canal of OME patients. Streptococci of the salivarius group and Acinetobacter lwoffii were more abundant in the nasopharynx of healthy controls than in OME patients. In addition to the microbiome analysis, 142 taxa were isolated from healthy individuals, and 79 isolates of 13 different Streptococcus species were tested for their pathobiont-inhibiting potential. Of these, Streptococcus salivarius isolates showed a superior capacity to inhibit the growth of H. influenzae, Moraxella catarrhalis, Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus aureus, A. otitis, and Corynebacterium otitidis. S. salivarius strains thus show potential as a probiotic for prevention or treatment of OME based on their overrepresentation in the healthy nasopharynx and their ability to inhibit the growth of respiratory pathobionts. (This study has been registered at ClinicalTrials.gov under registration no. NCT03109496.)

IMPORTANCE The majority of probiotics marketed today target gastrointestinal health. This study searched for bacteria native to the human upper respiratory tract, with a beneficial potential for respiratory and middle ear health. Comparison of the microbiomes of children with chronic otitis media with effusion (OME) and of healthy controls identified Streptococcus salivarius as a health-associated and prevalent inhabitant of the human nasopharynx. However, beneficial potential should be assessed at strain level. Here, we also isolated specific S. salivarius strains from the healthy individuals in our study. These isolates showed a beneficial safety profile and efficacy potential to inhibit OME pathogens in vitro. These properties will now have to be evaluated and confirmed in human clinical studies.

Dolosigranulum pigrum Cooperation and Competition in Human Nasal Microbiota

Staphylococcus aureus and Streptococcus pneumoniae infections cause significant morbidity and mortality in humans. For both, nasal colonization is a risk factor for infection. Studies of nasal microbiota identify Dolosigranulum pigrum as a benign bacterium present when adults are free of S. aureus or when children are free of S. pneumoniae. Here, we validated these in vivo associations with functional assays. We found that D. pigrum inhibited S. aureusin vitro and, together with a specific nasal Corynebacterium species, also inhibited S. pneumoniae. Furthermore, genomic analysis of D. pigrum indicated that it must obtain key nutrients from other nasal bacteria or from humans. These phenotypic interactions support the idea of a role for microbe-microbe interactions in shaping the composition of human nasal microbiota and implicate D. pigrum as a mutualist of humans. These findings support the feasibility of future development of microbe-targeted interventions to reshape nasal microbiota composition to exclude S. aureus and/or S. pneumoniae.

Multiple epidemiological studies identify Dolosigranulum pigrum as a candidate beneficial bacterium based on its positive association with health, including negative associations with nasal/nasopharyngeal colonization by the pathogenic species Staphylococcus aureus and Streptococcus pneumoniae. Using a multipronged approach to gain new insights into D. pigrum function, we observed phenotypic interactions and predictions of genomic capacity that support the idea of a role for microbe-microbe interactions involving D. pigrum in shaping the composition of human nasal microbiota. We identified in vivo community-level and in vitro phenotypic cooperation by specific nasal Corynebacterium species. Also, D. pigrum inhibited S. aureus growth in vitro, whereas robust inhibition of S. pneumoniae required both D. pigrum and a nasal Corynebacterium together. D. pigruml-lactic acid production was insufficient to account for these inhibitions. Genomic analysis of 11 strains revealed that D. pigrum has a small genome (average 1.86 Mb) and multiple predicted auxotrophies consistent with D. pigrum relying on its human host and on cocolonizing bacteria for key nutrients. Further, the accessory genome of D. pigrum harbored a diverse repertoire of biosynthetic gene clusters, some of which may have a role in microbe-microbe interactions. These new insights into D. pigrum’s functions advance the field from compositional analysis to genomic and phenotypic experimentation on a potentially beneficial bacterial resident of the human upper respiratory tract and lay the foundation for future animal and clinical experiments.

IMPORTANCEStaphylococcus aureus and Streptococcus pneumoniae infections cause significant morbidity and mortality in humans. For both, nasal colonization is a risk factor for infection. Studies of nasal microbiota identify Dolosigranulum pigrum as a benign bacterium present when adults are free of S. aureus or when children are free of S. pneumoniae. Here, we validated these in vivo associations with functional assays. We found that D. pigrum inhibited S. aureusin vitro and, together with a specific nasal Corynebacterium species, also inhibited S. pneumoniae. Furthermore, genomic analysis of D. pigrum indicated that it must obtain key nutrients from other nasal bacteria or from humans. These phenotypic interactions support the idea of a role for microbe-microbe interactions in shaping the composition of human nasal microbiota and implicate D. pigrum as a mutualist of humans. These findings support the feasibility of future development of microbe-targeted interventions to reshape nasal microbiota composition to exclude S. aureus and/or S. pneumoniae.

Upper Respiratory Tract Microbiome and Otitis Media Intertalk: Lessons from the Literature

Otitis media (OM) is one of the most common diseases occurring during childhood. Microbiological investigations concerning this topic have been primarily focused on the four classical otopathogens (Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pyogenes) mainly because most of the studies have been conducted with culture-dependent methods. In recent years, the introduction of culture-independent techniques has allowed high-throughput investigation of entire bacterial communities, leading to a better comprehension of the role of resident flora in health and disease. The upper respiratory tract (URT) is a region of major interest in otitis media pathogenesis, as it could serve as a source of pathogens for the middle ear (ME). Studies conducted with culture-independent methods in the URT and ME have provided novel insights on the pathogenesis of middle ear diseases through the identification of both possible new causative agents and of potential protective bacteria, showing that imbalances in bacterial communities could influence the natural history of otitis media in children. The aim of this review is to examine available evidence in microbiome research and otitis media in the pediatric age, with a focus on its different phenotypes: acute otitis media, otitis media with effusion and chronic suppurative otitis media.

Nasal microbiota dominated by Moraxella spp. is associated with respiratory health in the elderly population: a case control study

Background

The elderly (≥65 years) are one of the populations most at risk for respiratory tract infections (RTIs). The aim of this study was to determine whether nasal and/or oropharyngeal microbiota profiles are associated with age and RTIs.

Methods

Nasal and oropharyngeal swabs of 152 controls and 152 patients with an RTI were included. The latter group consisted of 72 patients with an upper respiratory tract infection (URTI) and 80 with a lower respiratory tract infection (LRTI). Both nasal and oropharyngeal swabs were subjected to microbiota profiling using amplicon sequencing of the 16S rRNA gene. Moraxella species were determined using quantitative real-time PCR and culture.

Results

Based on the microbiota profiles of the controls and the patients with an RTI, eight nasal and nine oropharyngeal microbiota clusters were defined. Nasal microbiota dominated by either Moraxella catarrhalis or Moraxella nonliquefaciens was significantly more prevalent in elderly compared to mid-aged adults in the control group (p = 0.002). Dominance by M. catarrhalis/nonliquefaciens was significantly less prevalent in elderly with an LRTI (p = 0.001) compared to controls with similar age.

Conclusions

Nasal microbiota dominated by M. catarrhalis/nonliquefaciens is associated with respiratory health in the elderly population.

Panel 4: Recent advances in understanding the natural history of the otitis media microbiome and its response to environmental pressures

OBJECTIVE

To perform a comprehensive review of otitis media microbiome literature published between 1^st July 2015 and 30th June 2019.

DATA SOURCES

PubMed database, National Library of Medicine.

REVIEW METHODS

Key topics were assigned to each panel member for detailed review. Draft reviews were collated and circulated for discussion when the panel met at the 20th International Symposium on Recent Advances in Otitis Media in June 2019. The final draft was prepared with input from all panel members.

CONCLUSIONS

Much has been learned about the different types of bacteria (including commensals) present in the upper respiratory microbiome, but little is known about the virome and mycobiome. A small number of studies have investigated the middle ear microbiome; however, current data are often limited by small sample sizes and methodological heterogeneity between studies. Furthermore, limited reporting of sample collection methods mean that it is often difficult to determine whether bacteria detected in middle ear fluid specimens originated from the middle ear or the external auditory canal. Recent in vitro studies suggest that bacterial interactions in the nasal/nasopharyngeal microbiome may affect otitis media pathogenesis by modifying otopathogen behaviours. Impacts of environmental pressures (e.g. smoke, nutrition) and clinical interventions (e.g. vaccination, antibiotics) on the upper respiratory and middle ear microbiomes remain poorly understood as there are few data.

IMPLICATIONS FOR PRACTICE

Advances in understanding bacterial dynamics in the upper airway microbiome are driving development of microbiota-modifying therapies to prevent or treat disease (e.g. probiotics). Further advances in otitis media microbiomics will likely require technological improvements that overcome the current limitations of OMICs technologies when applied to low volume and low biomass specimens that potentially contain high numbers of host cells. Improved laboratory models are needed to elucidate mechanistic interactions among the upper respiratory and middle ear microbiomes. Minimum reporting standards are critically needed to improve inter-study comparisons and enable future meta-analyses.

[Possibility of treatment chronic adenoiditis and otitis media with effusion in children, into account the role of the microbiota of the mucous of the nasopharynx]

In recent years, OME in childhood tends to increase. The low efficiency of the currently used traditional methods of conservative therapy and the high rate of relapse of the disease make it necessary to develop new methods of treatment. It is important that there is a connection of development of OME and hypertrophy of the lymphoid tissue of the nasopharynx, which in childhood is considered as a response to the respiratory antigenic virus-bacterial load. The spread of the inflammatory process to the auditory tube with persistence of pathogenic microorganisms in the structure of lymphoid tissue leads to the further development of otitis media effusion; but it is still debatable. All living microorganisms that inhabit a certain anatomical niche (viruses, bacteria, fungi, etc.) are called 'microbiota'. This term includes both commensals and pathogens. 'Microbiome' means the totality of all genes of all microorganisms that inhabit the study area. Thus, the microbiome can be called the collective microbiota genome. Microbiota disorder is a change in the quantitative and qualitative composition of microorganisms, called dysbiosis, and is important in the development of inflammatory pathology. Some drugs (including antibacterial ones) adversely affect indigenous bacteria. Indigenous microbiota develops in abundance in the observed biotope and forms resistance to excessive growth of pathogenic microorganisms. Only NGS sequencing allows to analyze entire mixed bacterial communities ('microbiomes'), which cannot be performed by other diagnostic methods. The use of the NGS sequencing method has proved the important role of microbiota in the development of chronic adenoiditis and OME in children. One of the promising remedies is the inclusion of lysozyme in the treatment regimen. Recent studies indicate the antibacterial and antiviral effects of lysozyme. The use of NGS sequencing made it possible to identify the relationship of the composition of microbiota with the course of chronic adenoiditis and otitis media effusion in children. Inclusion of lysozyme-containing drug Lizobact into therapy promotes colonization of the nasopharynx by indigenous microbiota, while the clinical picture improves.

Recent Perspectives on Gene-Microbe Interactions Determining Predisposition to Otitis Media

A comprehensive understanding about the pathogenesis of otitis media (OM), one of the most common pediatric diseases, has the potential to alleviate a substantial disease burden across the globe. Advancements in genetic and bioinformatic detection methods, as well as a growing interest in the microbiome, has enhanced the capability of researchers to investigate the interplay between host genes, host microbiome, invading bacteria, and resulting OM susceptibility. Early studies deciphering the role of genetics in OM susceptibility assessed the heritability of the phenotype in twin and triplet studies, followed by linkage studies, candidate gene approaches, and genome-wide association studies that have helped in the identification of specific loci. With the advancements in techniques, various chromosomal regions and genes such as FBXO11, TGIF1, FUT2, FNDC1, and others have been implicated in predisposition to OM, yet questions still remain as to whether these implicated genes truly play a causative role in OM and to what extent. Meanwhile, 16S ribosomal RNA (rRNA) sequencing, microbial quantitative trait loci (mbQTL), and microbial genome-wide association studies (mGWAS) have mapped the microbiome of upper airways sites and therefore helped in enabling a more detailed study of interactions between host polymorphisms and host microbiome composition. Variants of specific genes conferring increased OM susceptibility, such as A2ML1, have also been shown to influence the microbial composition of the outer and middle ear in patients with OM, suggesting their role as mediators of disease. These interactions appear to impact the colonization of known otopathogens (Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis), as well as Neisseria, Gemella, Porphyromonas, Alloprevotella, and Fusobacterium populations that have also been implicated in OM pathogenesis. Meanwhile, studies demonstrating an increased abundance of Dolosigranulum and Corynebacterium in healthy patients compared to those with OM suggest a protective role for these bacteria, thereby introducing potential avenues for future probiotic treatment. Incorporating insights from these genetic, microbiome, and host-pathogen studies will allow for a more robust, comprehensive understanding of OM pathogenesis that can ultimately facilitate in the development of exciting new treatment modalities.

Vitamin D and Otitis Media

PURPOSE OF REVIEW

To examine the relationship between vitamin D and otitis media.

RECENT FINDINGS

Vitamin D deficiency has been associated with several respiratory diseases, including otitis media. Vitamin D supplementation may reduce the risk of otitis media. This relationship may be explained by vitamin D supporting the immune system by upregulating antimicrobial peptides which are effective against otopathogens and biofilm formation, supporting a less inflammatory immune response, or promoting beneficial commensal bacteria. This review will explore risk factors of both otitis media and vitamin D deficiency, the evidence of vitamin D being beneficial for various forms of otitis media, and possible mechanisms of action.