Association of the sinonasal bacterial microbiome with clinical outcomes in chronic rhinosinusitis: a systematic review

Biodiversity of the Bacterial and Fungal Microbiome and Associated Inflammatory Cytokine Profile in Chronic Rhinosinusitis

BACKGROUND

Dysbiosis of the bacterial and fungal microbiome has been increasingly implicated in the pathogenesis of chronic rhinosinusitis (CRS). This study explores the relationship between microbiome and mycobiome biodiversity and type 2 (T2) versus non-type 2 (NT2) inflammation.

METHODS

Mucosal tissues from the ethmoid sinus were collected during endoscopic sinus (CRS) and skull base (controls) surgery between January 2020 and July 2021. Specimens underwent 16S rRNA (bacterial) and internal transcribed spacer (fungal) gene sequencing, along with cytokine analysis using the Luminex assay. Based on cytokine (IL-4, IL-5, IL-13) concentrations and the presence of eosinophils, CRS cases were classified into T2 or NT2 inflammatory profiles. The relationships between CRS endotype and the biodiversity of the microbiome and mycobiome were assessed.

RESULTS

Specimens from 92 patients (30 control, 31 CRSwNP, 31 CRSsNP) were included in the analyses. Among 62 CRS cases, 20 exhibited T2 inflammation and 42 exhibited NT2 inflammation. Compared with control specimens, NT2 specimens exhibited significantly lower amplicon sequence variants (mean difference -149, 95% CI [-261, -37], p = 0.007), Shannon index (-0.48 [-0.79, -0.16], p = 0.002), and Simpson index (-0.003 [-0.005, -0.001], p = 0.002) for bacterial alpha diversity. However, no significant differences in bacterial alpha diversity were observed between T2 specimens and controls, or between T2 and NT2 specimens. Fungal biodiversity did not differ significantly across endotype and control groups.

CONCLUSION

Dysbiosis of the sinus bacterial microbiome is more strongly associated with a NT2-mediated inflammatory profile than with a T2-mediated inflammatory profile.

Comparison between upper and lower airway microbiome profiles in chronic rhinosinusitis patients

BACKGROUND

Dysregulation of the airway microbiota is thought to contribute to airway inflammation in both chronic rhinosinusitis (CRS) and asthma. However, the relationship between the upper and lower airway microbiome remains unclear.

METHODS

Sinus and lung brushes were collected from 29 CRS participants undergoing sinus surgery. DNA was extracted and submitted for 16s rRNA microbiome sequencing. Alpha and beta diversity metrics, taxonomic composition, and differences between individual taxa were compared for paired sinus and bronchial samples.

RESULTS

Twenty-three out of 29 participants had sufficient samples for analysis. The mean (standard deviation) age was 51.59 (14.57) years, and 10 (44%) patients were female. Twelve (52%) patients had comorbid asthma. Sinus brushes had significantly higher alpha diversity indexes (Shannon and Faith) compared to bronchial brushes (p < 0.001). Beta diversity metrics were significantly different between the sinus and bronchial samples. Principal coordinate analysis showed no clustering of paired nasal and bronchial samples. Sinus brushes had significantly more Lawsonella, Corynebacterium, and Staphylococcus compared to bronchia brushes, while the latter were enriched in Tropheryma and Sphingomonas, among others (false discovery rate [FDR]-adjusted p < 0.01). Finally, CRS patients with comorbid asthma had significantly higher Pseudomonas and Peptoniphilus in sinus brushes and lower Prevotella in bronchial brushes when compared to non-asthmatics (FDR-adjusted p < 0.01).

CONCLUSION

The sinus and bronchial bacterial microbiomes differ in important ways. Our study suggests that migration of bacteria from the sinus into the lower airways is unlikely in patients with CRS.

Post-irradiation dysbiosis in patients with nasopharyngeal carcinoma having received radiotherapy - A pilot study

OBJECTIVE

To compare the changes in the sinonasal mucosa microbiome in patients with nasopharyngeal carcinoma (NPC) before and after radiotherapy (RT), and to explore the pathogenesis of post-irradiation chronic rhinosinusitis (PI-CRS) and its association with dysbiosis.

STUDY DESIGN

Prospective cohort study.

SETTING

Unicenter, Tertiary referral hospital.

METHODS

Included patients newly diagnosed with NPC. Samples of ostiomeatal complex mucosa were collected before and after RT. Microbiome analysis was conducted using 16S rRNA sequencing, and statistical analysis was performed. Subgroup analyses based on RT modality (proton therapy or photon therapy) RESULTS: Total of 18 patients were enrolled in the study, with 62.1% receiving intensity-modulated proton therapy (IMPT). Corynebacterium was the most dominant genus identified in both the pre- and post-RT groups, with a visible increase in Staphylococcus and a decrease in Fusobacterium genus in post-RT group. Alpha-diversity did not significantly differ between groups, although the beta-diversity analysis revealed a dispersed microbiota in the post-RT group. The functional prediction indicated a higher relative abundance of taxonomies associated with biofilm formation in the post-RT group. The subgroup analysis revealed the above changes to be more significant in patients who received photon therapy (Intensity modulated radiation therapy, IMRT).

CONCLUSIONS

This is the first study to analyze the microbiome of patients with NPC after IMPT. We identified similarities between the post-RT microenvironment and that reported in patients with CRS, with a more apparent change noted in patients treated with IMRT. Further investigation is required to further elucidate the pathogenesis of PI-CRS and its relationship to post-RT dysbiosis, particularly IMPT.

Fungal and Bacterial Microbiome in Sinus Mucosa of Patients with and without Chronic Rhinosinusitis

OBJECTIVES

Dysbiosis of the sinonasal microbiome has been implicated in the pathogenesis of chronic rhinosinusitis (CRS). However, the mycobiome remains largely understudied, and microbial alterations associated with specific CRS subtypes have yet to be delineated. The objective of this study is to investigate the fungal and bacterial microbiome of sinus mucosa in CRS patients with and without nasal polyposis (CRSwNP and CRSsNP) versus healthy controls.

METHODS

Sinus mucosa was obtained from 92 patients (31 CRSsNP, 31 CRSwNP, and 30 controls) undergoing endoscopic sinus/skull base surgery. Data regarding demographics, Lund-MacKay scores, and histopathology were collected. Fungal and bacterial microbiome analysis was performed utilizing internal transcribed spacer amplicon and 16S rRNA sequencing.

RESULTS

Beta diversity of the sinonasal mycobiome differed significantly between CRS and controls (p = 0.001) and between CRSwNP and controls (p = 0.049), but not between CRSwNP and CRSsNP (p = 0.32) nor between CRSsNP and controls (p = 0.06). With respect to the bacterial microbiome, significantly lower alpha diversity was observed between CRS and controls (p < 0.001), CRSwNP versus controls (p < 0.001), and CRSsNP versus controls (p < 0.001). Beta diversity was also significantly different at the genus level between CRSwNP and CRSsNP (p = 0.019), CRSwNP and controls (p = 0.002)), and CRSsNP and controls (p < 0.001). However, alpha and beta diversity did not differ significantly between CRS patients with/without eosinophils or correlate with Lund-MacKay scores.

CONCLUSIONS

Differences in mycobiota diversity in CRS patients in comparison with controls suggest that alterations in the mycobiome may contribute to disease pathogenesis. Our findings also confirmed that diminished diversity among bacterial communities is associated with CRS and that significant differences are present in microbial composition between CRSwNP and CRSsNP.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:1054-1062, 2024.

[Advances in next-generation sequencing technology to analyze the microbiome of patients with chronic sinusitis]

Chronic rhinosinusitis （CRS） is a chronic inflammatory disease of the sinus mucosa, and the pathogenesis of CRS has not been fully elucidated, and the impact of dysbiosis of the microbiome in the nasal cavity and even in the gut on the pathogenesis of CRS remains controversial. Next-generation sequencing technology, a culture-independent high-throughput sequencing method, contributes to a comprehensive understanding of the CRS microbiome. This article reviews the progress of research on the relevance of bacteria and other microorganisms to CRS and the microbial characteristics of the sinus and intestinal tract of patients with CRS, introduces next-generation sequencing technologies for the study of the CRS microbiome, and discusses the therapeutic prospects of CRS and the possibility of probiotic therapy.

Middle meatus microbiome in patients with eosinophilic chronic rhinosinusitis in a Japanese population

BACKGROUND

Chronic rhinosinusitis (CRS) is a common chronic inflammatory disease and is subdivided into eosinophilic and noneosinophilic forms. There are few reports investigating the nasal microbiome and its pathological functions in patients with CRS.

OBJECTIVE

We sought to analyze factors contributing to variations of the nasal microbiome in CRS, and on the basis of these factors, to elucidate whether the bacterial metabolites were related to the pathogenesis.

METHODS

Nasal swabs were collected, and the V3 to V4 variable region of the 16S ribosomal RNA gene was amplified and sequenced. Factors contributing to variations of the nasal microbiome in patients with CRS were compared. The most influential factor was whether CRS was eosinophilic, and we compared α- and β-diversity, bacterial species, and predictive bacterial functions between the 2 patient groups. In addition, the metabolites of the key bacteria were extracted, and we evaluated the predicted bacterial functions in airway epithelial cells.

RESULTS

In total, 110 patients with CRS and 33 control subjects were enrolled. On the basis of the factors of variation, it was found that patients with eosinophilic CRS (n = 65) had different microbiomes with weighted UniFrac β-diversity and lower α-diversity compared with those with noneosinophilic CRS (n = 45). A higher abundance of Fusobacterium nucleatum and an increased LPS pathway were observed in patients with noneosinophilic CRS compared with those with eosinophilic CRS. In airway epithelial cells, LPS derived from F nucleatum suppressed the expression levels of ALOX15 induced by TH2 cytokines.

CONCLUSIONS

The differences in the nasal microbiome may play a key role in the pathophysiology of CRS.

The Impact of Gender on Long-Term Quality of Life After Sinus Surgery for Chronic Rhinosinusitis

OBJECTIVE

To identify the impact of gender on the clinical outcomes of endoscopic sinus surgery (ESS) through the comparison of quality of life measures in female and male patients who undergo surgical treatment for chronic rhinosinusitis (CRS).

STUDY DESIGN

Prospective observational cohort study.

METHODS

Patients with CRS completed the 22-item Sino-Nasal Outcome Test (SNOT-22) and EuroQol 5-Dimension Survey (EQ-5D) preoperatively and annually for 5 years following ESS. Health utility values (HUV) were calculated from EQ-5D scores. Comparisons of cohort characteristics were performed with chi-square and t-tests. A multivariable linear mixed effects model evaluated changes in SNOT-22 and HUV over time by gender.

RESULTS

Among the 1268 patients (54% female) enrolled, 789 and 343 completed postoperative surveys at one and 5 years, respectively. Preoperatively, females experienced more severe symptoms: mean SNOT-22 score (51.1 ± 20.9 female vs. 44.7 ± 20.0 male, p < 0.001) and HUV (0.80 ± 0.14 female vs. 0.84 ± 0.11 male, p < 0.001). These gender differences were resolved by year one postoperatively (SNOT-22: p = 0.083; HUV: p = 0.465). Two years after surgery, however, females reported more severe symptoms (SNOT-22: 25.6 ± 20.7 female vs. 21.5 ± 17.4 male, p = 0.005; HUV: 0.88 ± 0.12 female vs. 0.90 ± 0.11 male, p = 0.018), a difference that persisted at year five. These gender-related differences remained after adjusting for age, race, ethnicity, nasal polyps, history of prior ESS, and smoking status (p < 0.001). Within-subject improvement was comparable between genders (SNOT-22: p = 0.869; HUV: p = 0.611).

CONCLUSION

Females with CRS reported more severe symptoms both before and 5 years after surgery compared to their male counterparts. Understanding the mechanism behind these gender-related differences is important for optimizing CRS treatment.

LEVEL OF EVIDENCE

2 Laryngoscope, 133:3319-3326, 2023.

The nasal microbiome in patients suffering from non-steroidal anti-inflammatory drugs-exacerbated respiratory disease in absence of corticosteroids

Chronic rhinosinusitis (CRS) is a chronic inflammatory disease phenotypically classified by the absence (CRSsNP) or presence of nasal polyps (CRSwNP). The latter may also be associated with asthma and hypersensitivity towards non-steroidal anti-inflammatory drugs (NSAID) as a triad termed NSAID-exacerbated respiratory disease (N-ERD). The role of the microbiome in these different disease entities with regard to the underlying inflammatory process and disease burden is yet not fully understood. To address this question, we measured clinical parameters and collected nasal samples (nasal mucosal fluids, microbiome swabs from middle meatus and anterior naris) of patients suffering from CRSsNP (n=20), CRSwNP (n=20) or N-ERD (n=20) as well as from patients without CRS (=disease controls, n=20). Importantly, all subjects refrained from taking local or systemic corticosteroids or immunosuppressants for at least two weeks prior to sampling. The nasal microbiome was analyzed using 16S rRNA gene amplicon sequencing, and levels of 33 inflammatory cytokines were determined in nasal mucosal fluids using the MSD platform. Patients suffering from N-ERD and CRSwNP showed significantly worse smell perception and significantly higher levels of type 2 associated cytokines IL-5, IL-9, Eotaxin and CCL17. Across all 4 patient groups, Corynebacteria and Staphylococci showed the highest relative abundances. Although no significant difference in alpha and beta diversity was observed between the control and the CRS groups, pairwise testing revealed a higher relative abundance of Staphylococci in the middle meatus in N-ERD patients as compared to CRSwNP (p<0.001), CRSsNP (p<0.01) and disease controls (p<0.05) and of Lawsonella in patients suffering from CRSwNP in middle meatus and anterior naris in comparison to CRSsNP (p<0.0001 for both locations) and disease controls (p<0.01 and p<0.0001). Furthermore, we observed a positive correlation of Staphylococci with IL-5 (Pearson r=0.548) and a negative correlation for Corynebacteria and Eotaxin-3 (r=-0.540). Thus, in patients refraining from oral and nasal corticosteroid therapy for at least two weeks known to alter microbiome composition, we did not observe differences in microbiome alpha or beta diversity between various CRS entities and disease controls. However, our data suggest a close association between increased bacterial colonization with Staphylococci and decreased colonization by Corynebacteria as well as increased type 2 inflammation.

Study on the Salivary Microbial Alteration of Men With Head and Neck Cancer and Its Relationship With Symptoms in Southwest China

This study explored the association between oral microbes and head and neck cancer (HNC) as well as symptoms related to patients with HNC before surgical treatment. Fifty-six patients with HNC and 64 matched healthy controls were recruited from West China hospital in Southwest China. The demographic, clinical, and symptom data were collected. Salivary samples were collected to determine the microbial characteristics using 16S rRNA gene sequencing. Patients with HNC presented increased Capnocytophaga abundances. The oral microbial markers as Capnocytophaga (area under the curve=0.81) achieved a high classification power between the HNC patients and healthy controls. Moreover, using Capnocytophaga in conjunction with symptom of voice/speech difficulty achieved an overall predicting accuracy of 92.5% comparing with using Capnocytophaga alone (79.2% accuracy) in distinguishing the HNC patients from healthy controls. Salivary microbial profiles and HNC symptoms may be potential biomarkers for HNC screening.