Impact of cigarette smoking on the middle meatus microbiome in health and chronic rhinosinusitis

The Role of the Gut and Airway Microbiota in Chronic Rhinosinusitis with Nasal Polyps: A Systematic Review

In recent years, there has been growing interest in understanding the potential role of microbiota dysbiosis or alterations in the composition and function of human microbiota in the development of chronic rhinosinusitis with nasal polyposis (CRSwNP). This systematic review evaluated the literature on CRSwNP and host microbiota for the last ten years, including mainly nasal bacteria, viruses, and fungi, following the PRISMA guidelines and using the major scientific publication databases. Seventy original papers, mainly from Asia and Europe, met the inclusion criteria, providing a comprehensive overview of the microbiota composition in CRSwNP patients and its implications for inflammatory processes in nasal polyps. This review also explores the potential impact of microbiota-modulating therapies for the CRSwNP treatment. Despite variability in study populations and methodologies, findings suggest that fluctuations in specific taxa abundance and reduced bacterial diversity can be accepted as critical factors influencing the onset or severity of CRSwNP. These microbiota alterations appear to be implicated in triggering cell-mediated immune responses, cytokine cascade changes, and defects in the epithelial barrier. Although further human studies are required, microbiota-modulating strategies could become integral to future combined CRSwNP treatments, complementing current therapies that mainly target inflammatory mediators and potentially improving patient outcomes.

Impact of dual electronic and conventional cigarette use on diagnosis and surgery for chronic rhinosinusitis: A multicenter study

KEY POINTS

Dual EC/CC users had a significantly greater risk of CRS or FESS when compared to solo users. Dual EC/CC users did not have a significantly greater risk of polyposis when compared to solo users. This effect likely relates to bacterial, immune cell, genetic, and mucociliary alterations.

Precision medicine in chronic rhinosinusitis - using endotype and endotype-driven therapeutic options

INTRODUCTION

Chronic rhinosinusitis (CRS) is a heterogeneous disease, and its complex pathophysiological characteristics pose a challenge to its clinical treatment. CRS is distinguished not only by clinical phenotype but also by endotype characteristics, which are divided into type 2 CRS and non-type 2 CRS.

AREAS COVERED

In this review, we summarize and discuss current studies that depict the mechanisms and endotypes of CRS. In particular, inflammatory cells and the microbiome play a role in the pathophysiology of CRS. We also listed some of the biomarkers described in recent studies that may serve as a theoretical foundation for additional investigations. We have summarized the advantages and disadvantages of existing treatments and listed the available biological treatments for CRS in detail.

EXPERT OPINION

Endotype-driven therapeutic options face many challenges because of the complexity of the disease. Glucocorticoids, nasal endoscopic surgery, and biological therapy are the main treatments used in clinical practice, but they have limitations. This review provides advice on the clinical management and treatment options for patients with different endotypes, which will be more conducive to improving the quality of life and reducing the financial burden on patients.

The Effects of Smoking on Human Pharynx Microbiota Composition and Stability

The oral microbiota is essential to the health of the host, yet little is known about how it responds to disturbances. We examined the oropharyngeal microbiota of 30 individuals over 40 weeks. As the oropharynx is an important gateway to pathogens, and as smoking is associated with increased incidence and severity of respiratory infections, we compared the microbiota of smokers and nonsmokers to shed light on its potential for facilitating infections. We hypothesized that decreased species diversity, decreased community stability, or increased differences in community structure could facilitate invading pathogens. We found that smoking is associated with reduced alpha diversity, greater differences in community structure, and increased environmental filtering. The effects of short-term perturbations (antibiotic use and participants exhibiting cold symptoms) were also investigated. Antibiotic use had a negative effect on alpha diversity, irrespective of smoking status, and both antibiotic use and cold symptoms were associated with highly unique bacterial communities. A stability analysis of models built from the data indicated that there were no differences in local or global stability in the microbial communities of smokers, compared to nonsmokers, and that their microbiota are equally resistant to species invasions. Results from these models suggest that smoker microbiota are perturbed but characterized by alternative stable states that are as stable and invasion-resistant as are the microbiota of nonsmokers. Smoking is unlikely to increase the risk of infectious disease through the altered composition and ecological function of the microbiota; this is more likely due to the effects of smoking on the local and systemic immune system. IMPORTANCE Smoking is associated with an increased risk of respiratory infections. Hypothetically, the altered community diversity of smokers' pharyngeal microbiota, together with changes in their ecological stability properties, could facilitate their invasion by pathogens. To address this question, we analyzed longitudinal microbiota data of baseline healthy individuals who were either smokers or nonsmokers. While the results indicate reduced biodiversity and increased species turnover in the smokers' pharyngeal microbiota, their ecological stability properties were not different from those of the microbiota of nonsmokers, implying, in ecological terms, that the smokers' microbial communities are not less resistant to invasions. Therefore, the study suggests that the increased propensity of respiratory infections that is seen in smokers is more likely associated with changes in the local and systemic immune system than with ecological changes in the microbial communities.

Prevalence and risk factors of chronic rhinosinusitis among Chinese: A systematic review and meta-analysis

Background

Chronic rhinosinusitis (CRS) can be seen in people of all ages. CRS heavily affects the quality of a patient's daily life and also causes tremendous economic burdens on patients' families and society. The prevalence of CRS in different countries varies and no systematic review of the prevalence of CRS among Chinese has been published previously. The objective of this systematic review and meta-analysis is to determine the prevalence of CRS among Chinese and to explore the main risk factors of CRS among Chinese.

Methods

Using relevant keywords, data resources including PubMed, Scopus, Web of Science, Google Scholar, Embase, Cochrane Library, Chinese National Knowledge of Infrastructure (CNKI), WANGFANG, VIP, and China Biomedical Literature database (CMB) were searched to obtain literature reporting the prevalence of and risk factors of CRS among Chinese which were clearly diagnosed with CRS from inception to 30 June 2022. The random/fixed effect model was used for meta-analysis, and the I² index was employed to assess heterogeneity among studies. All analyses were performed by using the STATA version 16.0 software. The study was registered with PROSPERO, register number. CRD42022341877.

Result

A total of 12 relevant kinds of literature were qualified for the present systematic review, including 4,033 patients. The results showed that the overall prevalence of CRS among Chinese was 10% (95%CI: 0.06-0.13, I² = 99.6%, P < 0.001). The prevalence of CRS among Chinese who lived in urban cities was 18% (95%CI: -0.07 to 0.43, I² = 99.9%, P < 0.001), which was obviously lower than the prevalence of CRS among Chinese who lived in rural areas (27%, 95%CI: -0.14 to 0.68, I² = 99.8%, P < 0.001). The prevalence of CRS among Chinese before 2010 was 23% (95%CI: -0.05 to 0.50, I² = 99.8%, P < 0.001), which was remarkably higher than the prevalence of CRS among Chinese after 2010 (7%, 95%CI: 0.05-0.09, I² = 99.0%, P < 0.001). The prevalence of CRS among Chinese who were divorced was 17% (95%CI: 0.12-0.22, I² = 0.0%, P = 0.436), while the prevalence of CRS among Chinese who were married, widowed, and unmarried was 9% (95%CI: 0.06-0.11, I² = 88.1%, P = 0.004), 9% (95%CI: 0.06-0.11, I² = 0.0%, P = 0.863), and 9% (95%CI: 0.08-0.10, I² = 0.0%, P = 0.658), respectively. The prevalence of CRS among Han and minority Chinese was 8% (95%CI: 0.07-0.10, I² = 69.6%, P = 0.070) and 12% (95%CI: 0.10-0.15, I² = 38.6%, P = 0.202), respectively. The prevalence of CRS among Chinese who was never exposed to moldy or damp environments was 8% (95%CI: 0.08-0.09, I² = 0.0%, P = 0.351), the prevalence of CRS among Chinese who was occasionally exposed to moldy or damp environments was 16% (95%CI: 0.10-0.22, I² = 78.9%, P = 0.030), and the prevalence of CRS among Chinese who was frequently or every day exposed to moldy or damp environments was up to 20% (95%CI: 0.15-0.24, I² = 0.0%, P = 0.558).

Conclusion

This meta-analysis shows that the prevalence of CRS among Chinese is at a high level. People who have some risk factors, such as occasional or frequent or everyday exposure to moldy or damp environments, have a higher prevalence of CRS. We should attach more importance to the risk factors of CRS in clinical practice and disseminate scientific information and carry out education to lower the prevalence of CRS in China.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=341877, identifier: CRD42022341877.

Expression of Major Lipid Raft Protein Raftlin in Chronic Rhinosinusitis with Nasal Polyps in Smoking and Non-Smoking Patients Correlated with Interleukin-17 and Tumor Necrosis Factor-α Levels

Raftlin, as an inflammatory biomarker, has been previously reported in chronic inflammatory diseases. This study investigates the expression of Raftlin in cigarette smokers and in chronic rhinosinusitis with nasal polyps (CRSwNP), as well as evaluating its correlation with interleukin-17 (IL-17) and tumor necrosis factor-α (TNF-α) levels. A total of 30 CRSwNP non-smoking and 16 CRSwNP + SK (smoking) patients undergoing endoscopic sinus surgery were enrolled, while 20 middle turbinate tissue pieces were examined and performed as the control group. In nasal mucosa epithelial staining, Raftlin levels were elevated in the columnar cells and were stained much more intensely in the CRSwNP and CRSwNP + SK groups. Raftlin was located more closely to the apical region of the epithelium in the CRSwNP + SK group; however, the Raftlin levels from whole nasal tissue pieces, according to ELISA data, showed that there was no significant difference between the three different study groups. A positive relationship by Pearson correlation was found between IL-17 or TNF-α levels and Raftlin levels. Taken together, these data indicate that increasing Raftlin expression in columnar cells might involve nasal epithelial remodeling in smokers with CRSwNP.

Unravelling the role of the microbiome in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a complex, heterogenous condition with likely infectious and inflammatory causative factors. Renewed interest in the role that microbes play in this condition has stemmed from advancements in microbe identification and parallel research that has implicated the role of the microbiome in other chronic inflammatory conditions. This clinical commentary provides a review of the current literature relevant to chronic rhinosinusitis. Particular focus is paid to factors specific to the investigation of the sinonasal microbiome, evidence for the role of dysbiosis in the disease state and influences that may impact the microbiome. Possible mechanisms of disease and therapeutic implications through microbial manipulation are also reviewed, as are deficiencies and limitations of the current body of research.

Influence of the Microbiome on Chronic Rhinosinusitis With and Without Polyps: An Evolving Discussion

Chronic rhinosinusitis (CRS) is widely prevalent within the population and often leads to decreased quality of life, among other related health complications. CRS has classically been stratified by the presence of nasal polyps (CRSwNP) or the absence nasal polyps (CRSsNP). Management of these conditions remains a challenge as investigators continue to uncover potential etiologies and therapeutic targets. Recently, attention has been given to the sinunasal microbiota as both an inciting and protective influence of CRS development. The healthy sinunasal microbiologic environment is largely composed of bacteria, with the most frequent strains including Staphylococcus aureus, Streptococcus epidermidis, and Corynebacterium genera. Disruptions in this milieu, particularly increases in S. aureus concentration, have been hypothesized to perpetuate both Th1 and Th2 inflammatory changes within the nasal mucosa, leading to CRS exacerbation and potential polyp formation. Other contributors to the sinunasal microbiota include fungi, viruses, and bacteriophages which may directly contribute to underlying inflammation or impact bacterial prevalence. Modifiable risk factors, such as smoking, have also been linked to microbiota alterations. Research interest in CRS continues to expand, and thus the goal of this review is to provide clinicians and investigators alike with a current discussion on the microbiologic influence on CRS development, particularly with respect to the expression of various phenotypes. Although this subject is rapidly evolving, a greater understanding of these potential factors may lead to novel research and targeted therapies for this often difficult to treat condition.

Unhealthy Lifestyle and Gut Dysbiosis: A Better Understanding of the Effects of Poor Diet and Nicotine on the Intestinal Microbiome

The study of the intestinal or gut microbiome is a newer field that is rapidly gaining attention. Bidirectional communication between gut microbes and the host can impact numerous biological systems regulating immunity and metabolism to either promote or negatively impact the host's health. Habitual routines, dietary choices, socioeconomic status, education, host genetics, medical care and environmental factors can all contribute to the composition of an individual's microbiome. A key environmental factor that may cause negative outcomes is the consumption of nicotine products. The effects of nicotine on the host can be exacerbated by poor dietary choices and together can impact the composition of the gut microbiota to promote the development of metabolic disease including non-alcoholic fatty liver disease. This review explores the contribution of nicotine, poor dietary choices and other unhealthy lifestyle factors to gut dysbiosis.

Evaluation of Smoking as a Modifying Factor in Chronic Rhinosinusitis

Importance

The negative association of smoking with the respiratory tract is well known; however, the association between smoking and chronic rhinosinusitis (CRS) has not been well characterized.

Objective

To analyze whether active smoking was a risk factor for CRS development, smoking was associated with disease-specific quality of life, and smokers experience an increased symptom burden than nonsmokers.

Design, Setting, and Participants

This subanalysis of the Chronic Rhinosinusitis Epidemiology Study (CRES), a prospective, questionnaire-based case-control study conducted between October 2007 and September 2013 was conducted across 30 UK tertiary/secondary care sites. Participants were identified at ear, nose, and throat outpatient clinics and classified into CRS phenotypes as per European Position Paper on Rhinosinusitis and Nasal Polyps 2012 criteria. The overall response rate of those identified to take part in the study was 66%. A total of 1535 questionnaires were returned, with 1470 considered eligible for inclusion. Data analysis was conducted in January 2020.

Main Outcomes and Measures

The CRES was designed to distinguish differences in socioeconomic status, geography, medical comorbidities, lifestyle, and quality of life between patients with CRS and healthy controls.

Results

A total of 1450 patients completed the smoking question, comprising 219 controls (15.1%; mean [SD] age, 47.3 [14.9] years; 143 women [68%]), 546 participants with CRS (37.7%; mean [SD] age, 51.8 [15.3] years; 259 women [53%]) without nasal polyps (CRSsNPs), and 685 participants (47.2%; mean [SD] age, 56.0 [14.5] years; 204 women [33%]) with CRS and nasal polyps/allergic fungal rhinosinusitis (CRSwNPs+). The mean age was similar, with a greater female preponderance in the control group and male in the CRSwNP group. The greatest number of active smokers was found among control participants (33 [15%]), with a lower rate of smokers in the patients with CRSwNPs+ (9.9%) and CRSsNPs (13.9%), respectively. We found a clinically significant difference in the mean difference in Sino-nasal Outcome Test (SNOT-22) scores between active smokers and nonsmokers for both CRS phenotypes (4.49, 12.25). In both CRS subgroups active smokers had significantly worse SNOT-22 scores than nonsmokers by a mean (SD) magnitude of 10 (18.99, 24.14) points. Nonsmokers also demonstrated a higher percentage of surgical procedures (1 or more), although this was not clinically or statistically different (0.34, 1.10).

Conclusions and Relevance

This questionnaire-based case-control study demonstrated a clinically significant symptom burden associated with active cigarette smoking, with worse SNOT-22 scores in the smoking cohort by a mean magnitude of 10 points. We could find no demonstrable evidence that smoking increases the likelihood of need for revision sinus surgery. Clinicians should encourage smoking cessation alongside general CRS medical management.

Specialized pro-resolving mediator lipidome and 16S rRNA bacterial microbiome data associated with human chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a clinical syndrome defined by symptoms including nasal congestion, facial pain and pressure, anosmia, and rhinorrhea lasting more than 12 weeks. Several mechanistically distinct processes lead to the development of clinical symptoms in CRS including innate immune dysfunction, dysregulated eicosanoid metabolism and perturbations in host-microbiome interactions [1]. We developed a database comprised of patient demographic information, lipid mediator metabolomic profiles, and 16S bacterial rRNA gene sequence data from 66 patients undergoing endoscopic sinus surgery. Briefly, ethmoid sinus tissue and middle meatal swabs were collected from patients, including non-CRS controls, CRS with polyps (CRSwNP), and CRS without polyps (CRSsNP). Lipid mediator pathways from arachidonic acid (AA) and docosahexanoic acid (DHA) were analyzed by liquid chromatography/tandem mass spectrometry. Bacterial taxa were profiled in parallel by 16S rRNA gene sequencing. This database provides a useful compendium of AA/DHA metabolomic profiles and associated bacterial microbiota in patients with varying disease subtypes, demographics, and risk factors/comorbidities.

Altered tissue specialized pro-resolving mediators in chronic rhinosinusitis

Current literature implicates arachidonic acid-derived leukotrienes and prostaglandins in the pathogenesis of chronic rhinosinusitis. However, other omega-3 and omega-6 derived lipid mediators, such as specialized pro-resolving mediators (SPMs), may also be important in chronic inflammatory disorders of the upper airway. We hypothesize that SPMs differ among CRS subtypes compared to controls and in relation to sinonasal microbiota. Ethmoid sinus tissue and middle meatal swabs were collected from a convenience sample of 66 subjects, including non-CRS controls, CRS with polyps (CRSwNP), and CRS without polyps (CRSsNP). Lipid mediator pathways were analyzed by liquid chromatography/tandem mass spectrometry. Bacterial taxa were profiled in parallel by 16S rRNA gene sequencing. Resolvin D2 was elevated in both CRSwNP (p = 0.00076) and CRSsNP (p = 0.030) compared with non-CRS controls. Lipoxin A4 was significantly increased in CRSwNP compared with CRSsNP (p = 0.000033) and controls (p = 0.044). Cigarette smoking was associated with significantly lower concentrations of several 15-lipoxygenase metabolites including resolvin D1 (p = 0.0091) and resolvin D2 (p = 0.0097), compared with never-smokers. Several of the lipid compounds also correlated with components of the sinonasal mucosal microbiota, including bacterial pathogens such as Pseudomonas aeruginosa. These data suggest that dysfunctional lipid mediator pathways in CRS extend beyond the traditional descriptions of leukotrienes and prostaglandins and include SPMs. Furthermore, dysregulated SPM signaling may contribute to persistent inflammation and bacterial colonization in CRS.

Association of Cotinine-Verified Cigarette Exposure with Chronic Rhinosinusitis in Korean Adults

Chronic rhinosinusitis is known to be influenced by cigarette exposure; however, this relationship is based on the presence of nasal polyps, and objective measurements of cigarette exposure in chronic rhinosinusitis are not well established. This study aimed to estimate the association between chronic rhinosinusitis and smoking status based on self-reported questionnaires and urinary cotinine levels according to the presence of nasal polyps. We analyzed a total of 23,621 participants who participated from the fifth Korea National Health and Nutrition Examination Survey (2010–2012). Serum total and specific IgE level were measured. Higher prevalence of chronic rhinosinusitis with nasal polyps was associated with current smoking status (OR = 1.43, 95% CI = 1.00–2.03). This association was prevalent in participants aged ≤ 50 years (OR = 1.76, 95% CI = 1.01–3.05), and higher urinary cotinine level showed correlation with higher prevalence of chronic rhinosinusitis with nasal polyps in this age group (OR = 1.04, 95% CI = 1.00–1.08). In addition, positive correlation between serum total IgE and urinary cotinine levels was greater in patients with chronic rhinosinusitis (β = 0.493, 95% CI = 0.071–0.916) than in controls (β = 0.062, 95% CI = 0.021–0.103). Aggressive smoking interventions should be performed in patients with chronic rhinosinusitis with nasal polyp, especially in cases of young adults or high serum IgE levels.

The Association Between Smoking and Gut Microbiome in Bangladesh

INTRODUCTION

Epidemiological studies that investigate alterations in the gut microbial composition associated with smoking are lacking. This study examined the composition of the gut microbiome in smokers compared with nonsmokers.

AIMS AND METHODS

Stool samples were collected in a cross-sectional study of 249 participants selected from the Health Effects of Arsenic Longitudinal Study in Bangladesh. Microbial DNA was extracted from the fecal samples and sequenced by 16S rRNA gene sequencing. The associations of smoking status and intensity of smoking with the relative abundance or the absence and presence of individual bacterial taxon from phylum to genus levels were examined.

RESULTS

The relative abundance of bacterial taxa along the Erysipelotrichi-to-Catenibacterium lineage was significantly higher in current smokers compared to never-smokers. The odds ratio comparing the mean relative abundance in current smokers with that in never-smokers was 1.91 (95% confidence interval = 1.36-2.69) for the genus Catenibacterium and 1.89 (95% confidence interval = 1.39-2.56) for the family Erysipelotrichaceae, the order Erysipelotrichale, and the class Erysipelotrichi (false discovery rate-adjusted p values = .0008-.01). A dose-response association was observed for each of these bacterial taxa. The presence of Alphaproteobacteria was significantly greater comparing current with never-smokers (odds ratio = 4.85, false discovery rate-adjusted p values = .04).

CONCLUSIONS

Our data in a Bangladeshi population are consistent with evidence of an association between smoking status and dosage with change in the gut bacterial composition.

IMPLICATIONS

This study for the first time examined the relationship between smoking and the gut microbiome composition. The data suggest that smoking status may play an important role in the composition of the gut microbiome, especially among individuals with higher levels of tobacco exposure.

Association between the sinus microbiota with eosinophilic inflammation and prognosis in chronic rhinosinusitis with nasal polyps

Dysbiosis of the sinus microbiome affects the pathophysiology of chronic rhinosinusitis with nasal polyps (CRSwNPs). We investigated whether the sinus microbiota in CRSwNPs is associated with eosinophilic inflammation, especially in relation to innate lymphoid cells (ILCs), prognosis, and serum extracellular vesicles (EVs). Middle meatal swabs and serum from 31 CRSwNPs patients and six healthy controls were analyzed by 16S ribosomal RNA sequencing. ILC2s and cytokines from sinonasal tissues were measured by flow cytometry and ELISA, respectively. The relative abundances (RAs) of bacteria were compared based on eosinophilic inflammation and surgical outcome. The correlations between sinus bacteria and ILC2s, cytokines, and serum EVs were analyzed. The compositions of sinus bacteria were different between groups at the genus level. In eosinophilic CRSwNPs patients, the RA of Anaerococcus was significantly decreased (P = 0.010), whereas that of Lachnoclostridium was significantly increased (P = 0.038) compared with that in controls. The RA of Lachnoclostridium showed a significant positive correlation with interleukin (IL)-5-producing ILC2 populations (R = 0.340, P = 0.049), whereas the RA of Anaerococcus showed a negative correlation with IL-5-producing ILC2 populations (R = −0.332, P = 0.055). The RAs of Corynebacterium, Anaerococcus, and Tepidimonas were significantly decreased in patients with suboptimal outcomes compared with those in patients with optimal outcomes and control subjects. Some sinus bacteria and serum EVs showed positive correlations. CRSwNPs patients showed distinct microbiota compositions based on eosinophilic inflammation in relation to ILC2s and surgical outcome. These findings support a relationship between the microbiota and the host immune response in CRSwNPs.

Microbes living in the sinonasal cavity seem to affect the immune responses and clinical outcomes of patients with an inflammatory disease that can cause lasting pain, pressure, and swelling in the sinuses. Ji Heui Kim from the Asan Medical Center in Seoul, South Korea, and colleagues collected nasal swabs and blood from 31 people suffering from chronic rhinosinusitis with nasal polyps and from six healthy control individuals. They identified several specific bacterial groups whose presence or absence was associated with the abundance of certain white blood cell populations, a sign of inflammation. Some of these groups were linked to patient outcomes after nasal surgery but additional groups were also observed. The findings could help lead to new treatment strategies or diagnostic biomarkers for patients with this sinus disorder.

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.

Anterior Nares Diversity and Pathobionts Represent Sinus Microbiome in Chronic Rhinosinusitis

It is generally believed that the microbiome plays a role in the pathophysiology of chronic rhinosinusitis (CRS), though its exact contribution to disease development and severity remains unclear. Here, samples were collected from the anterior nares, nasopharynx, and maxillary and ethmoid sinuses of 190 CRS patients and from the anterior nares and nasopharynx of 100 controls. Microbial communities were analyzed by Illumina sequencing of the V4 region of 16S rRNA. The phenotype and patient characteristics were documented, and several serum inflammatory markers were measured. Our data indicate a rather strong continuity for the microbiome in the different upper respiratory tract (URT) niches in CRS patients, with the microbiome in the anterior nares being most similar to the sinus microbiome. Bacterial diversity was reduced in CRS patients without nasal polyps compared to that in the controls but not in CRS patients with nasal polyps. Statistically significant differences in the presence/absence or relative abundance of several taxa were found between the CRS patients and the healthy controls. Of these, Dolosigranulum pigrum was clearly more associated with URT samples from healthy subjects, while the Corynebacterium tuberculostearicum, Haemophilus influenzae/H. aegyptius, and Staphylococcus taxa were found to be potential pathobionts in CRS patients. However, CRS versus health as a predictor explained only 1 to 2% of the variance in the microbiome profiles in an adonis model. A history of functional endoscopic sinus surgery, age, and sex also showed a minor association. This study thus indicates that functional studies on the potential beneficial versus pathogenic activity of the different indicator taxa found here are needed to further understand the pathology of CRS and its different phenotypes. (This study has been registered at ClinicalTrials.gov under identifier NCT02933983.)IMPORTANCE There is a clear need to better understand the pathology and specific microbiome features in chronic rhinosinusitis patients, but little is known about the bacterial topography and continuity between the different niches of the upper respiratory tract. Our work showed that the anterior nares could be an important reservoir for potential sinus pathobionts. This has implications for the diagnosis, prevention, and treatment of CRS. In addition, we found a potential pathogenic role for the Corynebacterium tuberculostearicum, Haemophilus influenzae/H. aegyptius, and Staphylococcus taxa and a potential beneficial role for Dolosigranulum Finally, a decreased microbiome diversity was observed in patients with chronic rhinosinusitis without nasal polyps compared to that in healthy controls but not in chronic rhinosinusitis patients with nasal polyps. This suggests a potential role for the microbiome in disease development or progression of mainly this phenotype.

Cigarette smoke exposure redirects Staphylococcus aureus to a virulence profile associated with persistent infection

Tobacco smoking represents the leading preventable cause of death worldwide. Smoking is a recognised risk factor for several pathologies and is detrimental to host immune surveillance and defence. However, the impact of smoking on microbial residents of the nasopharyngeal cavity, in contact with cigarette smoke (CS), is lacking. Staphylococcus aureus is a major human pathogen that colonises the human nasopharynx and causes a wide range of infections. We investigated the impact of CS on specific virulence phenotypes important in S aureus pathogenesis. We observed strain-dependent differences following exposure to CS, namely growth inhibition, augmented biofilm formation, increased invasion of, and persistence within, bronchial alveolar epithelial cells. Additionally, we confirm the critical role of a functional accessory gene regulator (Agr) system in mediating increased biofilm development and host cell invasion and persistence following CS exposure. Furthermore, CS exposure resulted in reduced toxin production. Importantly, exposure of S aureus to CS accelerated the frequency of mutations and resulted in a significant increase in gentamicin-resistant small colony variant (SCV) formation. Mutational analysis revealed that CS induced SCVs emerge via the SOS response DNA mutagenic repair system. Taken together, our results suggest that CS redirects certain S aureus strains to a virulence profile associated with persistence.

The difference in nasal bacterial microbiome diversity between chronic rhinosinusitis patients with polyps and a control population

BACKGROUND

Little is known regarding the role of the microbiome of the paranasal sinuses and its contribution to sinus mucosal health and disease. Consequently, we examined the microbiome of chronic rhinosinusitis patients with polyps (CRSwNP) and a control population to provide new insights into the microbiota associated with the pathogenesis of CRSwNP.

METHODS

Fifty-nine CRSwNP patients and 27 controls were enrolled in the study. The bacterial communities of the middle meatus were detected using 16S ribosomal RNA (rRNA)-targeted Illumina MiSeq sequencing after microbial DNA was extracted from swabs.

RESULTS

Although there was no difference in diversity between the 2 groups, richness was lower in the CRSwNP group than in the control group (p = 0.03). At the phylum level, Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were predominant in both groups; however, the relative abundance was different, with the proportions of Actinobacteria (predominantly Corynebacterium) and Dolosigranulum being significantly higher in the control group than in the CRSwNP group.

CONCLUSION

These results support the theory of microbial dysbiosis as the pathogenesis of CRSwNP. The reduction in the proportions of potentially protective bacteria may decrease the overall stability of the sinonasal bacterial community.

Inflammatory Endotypes and Microbial Associations in Chronic Rhinosinusitis

A complex mix of inflammatory and microbial associations underscores the chronic inflammatory condition chronic rhinosinusitis (CRS), and the etiology remains poorly understood. Recent work has begun to delineate between variants (endotypes) of CRS on the basis of inflammatory biomarkers. This study aimed to assess inflammatory patterns in CRS phenotypes, identify putative endotypes of CRS, and to assess inflammatory associations with the sinonasal microbiota. Ten cytokines and six inflammatory cell types were assessed in mucosal biopsies from 93 CRS subjects and 17 controls via cytometric bead array and immunohistochemical techniques. Putative endotypes were identified via cluster analysis of subjects on the basis of inflammatory markers and comorbidities including polyposis, asthma, and aspirin sensitivity. Finally, previously published bacterial data for this cohort were reanalyzed to evaluate associations with inflammatory markers and CRS subtypes. Inflammatory patterns were highly variable within standard CRS phenotypes. Cluster analysis identified eight subject clusters, with strong delineation on the basis of polyposis and asthma, but also subtle distinctions in inflammatory markers. An association was also identified between depletion of several "health-associated" bacterial taxa, reduced bacterial diversity and increased overall bacterial load, with markers of inflammation and clinical severity. This study contributes to ongoing efforts to define distinct endotypes of CRS on the basis of underlying inflammatory processes, and also offers compelling evidence of a link between bacterial community dysbiosis and inflammation in CRS. Further resolving the heterogeneity of CRS is vital to inform clinical management and personalized treatment approaches.

Determinants of the Nasal Microbiome: Pilot Study of Effects of Intranasal Medication Use

Introduction

A role for bacteria and other microbes has long been suspected in the chronic inflammatory sinonasal diseases. Recent studies utilizing culture-independent, sequence-based identification have demonstrated aberrant shifts in the sinus microbiota of chronic rhinosinusitis subjects, compared with ostensibly healthy controls. Examining how such microbiota shifts occur and the potential for physician-prescribed interventions to influence microbiota dynamics are the topics of the current article.

Methods

The nasal cavity microbiota of 5 subjects was serially examined over an 8-week period using pan-bacterial 16S rRNA gene sequencing. Four of the subjects were administered topical mometasone furoate spray, while 1 subject underwent a mupirocin decolonization procedure in anticipation of orthopedic surgery.

Results

Measures of microbial diversity were unaffected by intranasal treatment in 2 patients and were markedly increased in the remaining 3. The increase in microbial diversity was related to clearance of Moraxella spp. and a simultaneous increase in members of the phylum Actinobacteria. Both effects persisted at least 2 weeks beyond cessation of treatment. Transient changes in the relative abundance of several bacterial genera, including Staphylococcus and Priopionibacteria, were also observed during treatment.

Conclusions

The effects of intranasal steroids on the sinonasal microbiome are poorly understood, despite their widespread use in treating chronic sinonasal inflammatory disorders. In this longitudinal study, administration of intranasal mometasone furoate or mupirocin resulted in shifts in microbial diversity that persisted to some degree following treatment cessation. Further characterization of these effects as well as elucidation of the mechanism(s) underlying these changes is needed.

Systematic Review and Meta-analysis of SNOT-22 Outcomes after Surgery for Chronic Rhinosinusitis with Nasal Polyposis

Objective Wide variation exists regarding reported outcomes after endoscopic sinus surgery (ESS) for chronic rhinosinusitis with nasal polyps (CRSwNP). This study seeks to combine data across studies to generate a summary measure and explore factors that might lead to variation. Data Sources OVID Medline, Scopus, EbscoHost, Database of Abstracts and Reviews of Effects, Health Technology Assessment, and National Health Service Economic Evaluation Database. Review Methods A search was performed following the PRISMA guidelines. Two independent researchers conducted a search using the mentioned data sources. Studies published before August 29, 2016, that involved ESS to treat CRSwNP were included. Mean changes in Sinonasal Outcome Test-22 (SNOT-22) scores were determined through metaregression of the following independent variables: publication year, sex, age, allergy status, asthma, tobacco use, prior surgery, follow-up length, and preoperative SNOT-22. Results Fifteen articles with 3048 patients treated with ESS met inclusion criteria. Pooled analyses of SNOT-22 scores revealed a mean change of 23.0 points (95% CI, 20.2-25.8; P < .001). A metaregression of patient factor effects on the mean change of SNOT-22 scores demonstrated that age ( r = 0.71, P = .01), asthma ( r = 0.21, P = .01), prior ESS ( r = 0.29, P = .01), and preoperative SNOT-22 score ( r = 0.4, P < .01) correlated with greater improvement in SNOT-22 scores. Tobacco use ( r = -0.91, P = .01) and longer lengths of follow-up ( r = -0.45, P < .01) were associated with less improvement in SNOT-22 scores. Conclusions Quality-of-life outcomes are significantly improved after ESS among patients with CRSwNP. Patient-specific factors may affect the degree of SNOT-22 change after surgery.

Chronic Rhinosinusitis: Potential Role of Microbial Dysbiosis and Recommendations for Sampling Sites

Chronic rhinosinusitis (CRS) is an inflammatory condition that affects up to 12% of the human population in developed countries. Previous studies examining the potential role of the sinus bacterial microbiota within CRS infections have found inconsistent results, possibly because of inconsistencies in sampling strategies. The aim of this study was to determine whether the sinus microbiome is altered in CRS and additionally if the middle meatus is a suitable representative site for sampling the sinus microbiome. Swab samples were collected from 12 healthy controls and 21 CRS patients, including all eight sinuses for CRS patients and between one and five sinuses for control subjects. The left and right middle meatus and nostril swabs were also collected. Significant differences in the sinus microbiomes between CRS and control samples were revealed using high-throughput 16S rRNA gene sequencing. The genus Escherichia was over-represented in CRS sinuses, and associations between control patients and Corynebacterium and Dolosigranulum were also identified. Comparisons of the middle meatuses between groups did not reflect these differences, and the abundance of the genus Escherichia was significantly lower at this location. Additionally, intra-patient variation was lower between sinuses than between sinus and middle meatus, which together with the above results suggests that the middle meatus is not an effective representative sampling site.

A Systematic Review of the Association between Cigarette Smoke Exposure and Chronic Rhinosinusitis

Objectives Cigarette smoking and passive smoke exposure have been associated with chronic rhinosinusitis (CRS). Our goal in this systematic review was to (1) determine if there was a strong correlative effect in large population studies between cigarette smoke exposure and the prevalence of CRS, (2) investigate pathogenic mechanisms of cigarette smoke in the upper airway, and (3) determine if a history of cigarette smoking affects the medical and surgical outcomes of CRS. Data Sources MEDLINE, Embase, Cochrane CENTRAL, Web of Science SCI and CPCI-S, and websites. Methods A comprehensive literature review and quantitative meta-analysis of studies based on the PRISMA protocol and examining the relationship between cigarette smoke exposure and CRS was performed. A search strategy was developed using various terms such as sinusitis, rhinitis, rhinosinusitis, and smoking. The articles were categorized by (1) epidemiology, (2) pathophysiology, and (3) outcomes. Data regarding study design, population/setting, methods, and bias were collected. Results The initial search generated 2621 titles/abstracts with 309 articles undergoing secondary review and 112 articles for final review. We determined that there is a strong correlation between active and passive cigarette smoke with the prevalence of CRS. Cigarette smoke challenge to sinonasal epithelia results in the release of inflammatory mediators and altered ciliary beat frequency. Pediatric patients exposed to secondhand smoke appear to have particularly poor outcomes. Conclusion There is clear evidence that cigarette smoke is related to CRS, but longitudinal and mechanistic studies are required to determine a causative effect. This information is critical for greater understanding of CRS health outcomes.

Therapy of Sinonasal Microbiome in CRS: A Critical Approach

PURPOSE OF REVIEW

Perturbations in local microbiota have been demonstrated in many chronic inflammatory diseases including chronic rhinosinusitis (CRS). The purpose of this paper is to review the latest microbiome research as it pertains to CRS and establish whether there is any evidence supporting the microbiome hypothesis for CRS. Treatment factors that may influence the sinonasal microbiome as well as the role of probiotics are also discussed.

RECENT FINDINGS

Despite significant heterogeneity in study design, tissue sampling, processing and bioinformatics analysis, consistent findings have emerged from the recent literature. Healthy individuals and CRS patients have similar overall bacterial burden of disease and share many common phylum. CRS patients, however, routinely show reductions in markers of biodiversity. Both medical and surgical treatments appear to influence the sinonasal microbiome, with certain bacterial strains associated with better treatment outcomes. The presence of microbial dysbiosis in CRS is now supported by numerous studies. Whether this dysbiosis is a cause or rather an association of the disease process still remains unclear. Although probiotic therapies show early promise, much larger studies are required to establish their real role as a treatment for CRS.

Chronic Rhinosinusitis and the Evolving Understanding of Microbial Ecology in Chronic Inflammatory Mucosal Disease

Chronic rhinosinusitis (CRS) encompasses a heterogeneous group of debilitating chronic inflammatory sinonasal diseases. Despite considerable research, the etiology of CRS remains poorly understood, and debate on potential roles of microbial communities is unresolved. Modern culture-independent (molecular) techniques have vastly improved our understanding of the microbiology of the human body. Recent studies that better capture the full complexity of the microbial communities associated with CRS reintroduce the possible importance of the microbiota either as a direct driver of disease or as being potentially involved in its exacerbation. This review presents a comprehensive discussion of the current understanding of bacterial, fungal, and viral associations with CRS, with a specific focus on the transition to the new perspective offered in recent years by modern technology in microbiological research. Clinical implications of this new perspective, including the role of antimicrobials, are discussed in depth. While principally framed within the context of CRS, this discussion also provides an analogue for reframing our understanding of many similarly complex and poorly understood chronic inflammatory diseases for which roles of microbes have been suggested but specific mechanisms of disease remain unclear. Finally, further technological advancements on the horizon, and current pressing questions for CRS microbiological research, are considered.

Bacterial Pathogens and the Microbiome

Bacterial pathogens and microbiome alterations can contribute to the initiation and propagation of mucosal inflammation in chronic rhinosinusitis (CRS). In this article, the authors review the clinical and research implications of key pathogens, discuss the role of the microbiome, and connect bacteria to mechanisms of mucosal immunity relevant in CRS.

Bacterial community collapse: a meta-analysis of the sinonasal microbiota in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a common, debilitating condition characterized by long-term inflammation of the nasal cavity and paranasal sinuses. The role of the sinonasal bacteria in CRS is unclear. We conducted a meta-analysis combining and reanalysing published bacterial 16S rRNA sequence data to explore differences in sinonasal bacterial community composition and predicted function between healthy and CRS affected subjects. The results identify the most abundant bacteria across all subjects as Staphylococcus, Propionibacterium, Corynebacterium, Streptococcus and an unclassified lineage of Actinobacteria. The meta-analysis results suggest that the bacterial community associated with CRS patients is dysbiotic and ecological networks fostering healthy communities are fragmented. Increased dispersion of bacterial communities, significantly lower bacterial diversity, and increased abundance of members of the genus Corynebacterium are associated with CRS. Increased relative abundance and diversity of other members belonging to the phylum Actinobacteria and members from the genera Propionibacterium differentiated healthy sinuses from those that were chronically inflamed. Removal of Burkholderia and Propionibacterium phylotypes from the healthy community dataset was correlated with a significant increase in network fragmentation. This meta-analysis highlights the potential importance of the genera Burkholderia and Propionibacterium as gatekeepers, whose presence may be important in maintaining a stable sinonasal bacterial community.

The sinonasal bacterial microbiome in health and disease

PURPOSE OF REVIEW

The development of culture-independent bacterial DNA sequencing techniques and integration into research practice has led to a burgeoning interest in the microbiome and its relevance to human health and disease. Introduction into the study of chronic rhinosinusitis in the past few years has shaped current thinking on the role of bacteria in the disease process.

RECENT FINDINGS

Rich and diverse populations of bacteria inhabit the sinonasal cavity at all times. Decreased bacterial richness and diversity may be associated with disease state and outcomes.

SUMMARY

Although there is much to be explored, the sinus microbiome appears to have potentially promising roles in many aspects of sinus health and disease.

Risk Factors and Comorbidities in Chronic Rhinosinusitis

Chronic rhinosinusitis (CRS) is a heterogeneous disorder that creates a significant burden on the healthcare system. It is caused by a combination of inflammatory, environmental, and host factors; however, the precise mechanism of how each factor leads to CRS continues to be a source of debate. Previous data regarding this topic is often inconsistent or of lower quality. In this article, we review the recent literature on the risk factors and comorbidities in CRS. Large population-based studies have helped establish smoking as a significant risk factor for CRS. The focus has now shifted towards smoking and its effect on long-term outcomes after endoscopic sinus surgery (ESS). Ciliary dyskinesia, both primary and secondary, can affect both the sinonasal cavity and lower airways simultaneously by decreasing the beat frequency of cilia and inducing mucostasis. The effects of secondary dyskinesia may be reversible and there is some evidence to suggest the use of topical mucolytics in patients with CRS. Allergy and variants of sinonasal anatomy have been hypothesized to increase the risk of developing CRS by inducing chronic inflammation and obstructing the sinus ostia. Nevertheless, emerging data regarding these topics continue to produce inconclusive results. Inflammation of the upper and lower airways can occur simultaneously as seen in patients with asthma and aspirin sensitivity. The connection between these pro-inflammatory disease states has been known for many years. Newer evidence include large population-based studies and studies that correlate objective tests, such as computer tomography scans to pulmonary function tests. However, the treatment of CRS and its effects on obstructive airway disease continues to be a topic of debate. More large prospective studies are needed in order to continue refining our knowledge of the disease processes in CRS.

Next Generation Sequencing and the Microbiome of Chronic Rhinosinusitis: A Primer for Clinicians and Review of Current Research, Its Limitations, and Future Directions

OBJECTIVE

Microbiomics in chronic diseases, including chronic rhinosinusitis (CRS), have undergone rapid advances in recent times. The introduction of Next Generation Sequencing (NGS) technology has produced significant clinical insights regarding the bacteriology of these conditions. We review studies that have used 16S rRNA sequencing to specifically investigate the microbiota profiles of patients with CRS in a variety of contexts.

METHODS

Literature review using the CINAHL, MEDLINE, PUBMED, and the Cochrane databases. Papers utilizing 16S-sequencing technology on CRS specimens published between January 1, 1995, and October 31, 2015, were included. Studies limited to only healthy controls were excluded.

RESULTS

Consistent with published studies using non-NGS techniques, the main genera commonly identified from the sinuses of CRS patients included Staphylococcus, Propionibacterium, and Corynebacterium. The microbiome of CRS patients had lower bacterial diversity compared to controls in a number of studies. Also consistent with non-NGS-based studies, Staphylococcus was implicated as an important genus, with highly colonized patients having worse surgical outcomes. Conflicting reports of antibiotic effects on the CRS microbiome were observed. Sampling methods were well investigated, many of the studies reviewed failed to include important methodological detail.

CONCLUSION

While 16S sequencing is a novel microbiological laboratory method, current studies have confirmed our existing understanding of bacteriology of CRS without providing significant additional clinical insight. Complementing 16S studies with more complex NGS methods while developing robust clinical studies aimed at shifting the disrupted CRS microbiome will provide researches with the opportunity to derive further clinical insight and develop new therapeutic targets.