Respiratory Tract Microbiota Research Articles

Distinct lower respiratory tract microbiota profiles linked to airway mucus hypersecretion in children with Mycoplasma pneumoniae pneumonia

BackgroundAirway mucus hypersecretion (AMH) can occur in children with acute respiratory diseases, but its underlying mechanisms and relationship with the lower respiratory tract microbiota (LRTM) are not yet fully understood. This study investigates the characteristics of LRTM in children with Mycoplasma pneumoniae pneumonia (MPP) and its impact on AMH.MethodsWe collected bronchoalveolar lavage fluid and related clinical indicators from 202 children with MPP. 16S rRNA gene amplicon sequencing was used for detection and identification. Microbial diversity and characteristic genera were compared, and their abundance was analyzed for correlations with clinical factors.ResultsAs the disease course (days from onset to bronchoscopy, grouped into T1, T2, T3) extended, α-diversity of the LRTM gradually increased, particularly in the T3 hypersecretion group. Moreover, significant differences were observed in the incidence of AMH, co-infection rates, peripheral white blood cell (WBC) count, and C-reactive protein levels. In AMH, Mycoplasmoides and Veillonella abundance and peripheral neutrophils were risk factors for increased secretions. In addition, in the T3 co-infection group, Streptococcus and Prevotella increased, replacing Stenotrophomonas as the dominant genus, possibly due to β-lactam antibiotic use. Prevotella abundance was strongly correlated with WBC.ConclusionThe composition and structure of LRTM in children with MPP played a crucial role in AMH and disease progression.

Post-viral lung diseases: the microbiota as a key player

Viral infections of the respiratory tract can lead to chronic lung injury through immunopathological mechanisms that remain unclear. Communities of commensal bacteria colonizing the respiratory tract, known as the respiratory tract microbiota, are altered in viral infections, which can contribute to inflammation, lung epithelial damage and subsequent development of lung disease. Emerging evidence on post-viral lung injury suggests an interplay between viral infections, immune responses and airway microbiota composition in the development of viral-induced lung diseases. In this review, we present the clinical characteristics of post-viral lung injury, along with the underlying immunopathological mechanisms and host-bacteria interactions, with a focus on influenza virus, respiratory syncytial virus and coronaviruses. Additionally, considering the important role of the airway microbiota in viral-induced pulmonary sequelae, we suggest key areas for future research on respiratory microbiota involvement in the development of post-viral lung diseases.

Assessment of lower respiratory tract microbiota associated with pulmonary tuberculosis in children.

The respiratory microbiota plays a crucial role in the development of tuberculosis (TB). While existing research has underscored imbalances in the respiratory microbiota of adult patients with TB, information regarding the lower respiratory tract (LRT) microbiota in pediatric patients with TB remains scarce. We employed 16S rRNA gene sequencing technology to investigate the LRT microbial communities of 85 children of different ages with active TB of different severities, 33 children with infectious diseases other than TB, and 48 sex- and age-matched healthy children. A marked imbalance in the respiratory microbiota was observed in children with TB, highlighted by reduced alpha diversity and a distinct microbial community structure. Comparative analysis indicated that patients with severe TB exhibited lower Neisseria levels than those with non-severe TB (1.01% vs. 3.93%, respectively; p = .02). Streptococcus and Gemella levels were lower in bacteriologically confirmed TB cases compared with clinically diagnosed cases, and higher in healthy children younger than 10 years old than in the older group. Spearman correlation analysis demonstrated significant associations between the microbiota of the LRT and cytokine concentrations in the sputum of children with TB (e.g., an inverse correlation between Veillonella and interleukin-17A). TB induced significant dysbiosis in the LRT microbiota of children that was associated with disease severity and the immunological response in the respiratory tract. Our findings may offer a deeper understanding of the role of the respiratory microbiome in TB pathogenesis and progression.

Lower respiratory tract microbiota in patients with clinically suspected nontuberculous mycobacterial pulmonary disease according to the presence of gastroesophageal reflux.

Although gastroesophageal reflux has been recognized as one of the risk factors of nontuberculous mycobacterial pulmonary disease (NTM-PD) progression, the effect of reflux on the lower respiratory tract microbiota has not been studied in detail. We investigated the composition of the lower respiratory tract microbiota in patients with clinically suspected NTM-PD, comparing them based on the presence of reflux. Forty-seven patients suspected of having NTM-PD were enrolled and assigned according to presence of reflux (n = 22) and non- reflux (n = 25). We performed a pepsin ELISA assay to identify the presence of reflux and 16S ribosomal RNA gene amplicon sequencing to evaluate the microbiota in bronchoalveolar lavage fluid. There were no significant differences in the diversity or composition of the lower respiratory microbiota between the NTM-PD and non-NTM-PD groups. Bacterial richness was observed in the non-reflux group than in the reflux group [P = 0.03] and a cluster in the reflux group was observed. The reflux group showed a predominance for Pseudomonas aeruginosa or Staphylococcus aureus among the NTM-PD group and for P. aeruginosa, Haemophilus influenzae, Klebsiella pneumoniae, or Eikenella species among the non-NTM-PD group. The non-reflux groups presented diverse patterns. A linear discriminant analysis and volcano plot demonstrated that P. aeruginosa, H. haemolyticus, Selenomonas artemidis, and Dolosigranulum pigrum were specifically associated with the NTM-PD reflux group, while P. aeruginosa was specifically associated with the non-NTM-PD reflux group. These observations confirm that the lower respiratory microbiota is consistently altered by reflux but not in NTM-PD.

Changes in respiratory tract and gut microbiota in AR mice and their relationship with Th1/Th2/Treg

BackgroundThe etiology of allergic rhinitis (AR) is not fully understood. Studies have shown that the maturation of children's immune systems is closely related to microecology. However, few studies have focused simultaneously on changes in respiratory and gut microbiota in AR and their correlation between microecological changes and Th1/Th2/Treg. ObjectiveThe aim is to investigate the pathogenesis of AR based on respiratory microecology, gut microecology, and Th1/Th2/Treg levels by applying microbiome techniques and correlation analysis. MethodsStandardized OVA-induced AR mice were established. Serum OVA-sIgE, IL-4, IFN-γ, IL-10 were measured by ELISA, Tregs in lymph nodes were determined by flow cytometry, and the histological characteristics of nasal tissues were evaluated by Hematoxylin & Eosin (H&E). Nasal symptoms were observed to determine the reliability of the AR mouse model. Nasal lavage fluid (NALF) and fecal samples were collected after the last OVA challenge. The composition of respiratory microbiota in NALF and gut microbial in feces samples via 16S rRNA gene sequencing between the two groups, further explored the relationship between microbiota and Th1/Th2/Treg levels. ResultsIn the AR group, the incidence of nose rubbing and sneezing in each mouse was significantly increased compared with the control group (all P < 0.001) and the inflammatory cell infiltration of NALF shows a significant increase in eosinophilic and neutrophilic infiltrates upon the AR group; H&E showed that the nasal mucosa of AR mice infiltration of massive eosinophils cells and neutrophils cells. OVA-sIgE and IL-4 in the AR group were increased (P < 0.01, P < 0.05) and IFN-γ, IL-10 were significantly decreased (P < 0.01, P < 0.05). Tregs showed a downward trend in the AR group, but there was no statistical difference. Compared with the control group, the respiratory microbiota of AR mice did not change significantly, while the gut microbiota changed significantly. In gut microbiota, compared to the control group, Shannon index in the AR group revealed a significant decrease at the genus level (P < 0.01), and Simpson index was significantly increased at all levels (all P < 0.05). PCoA also showed significant differences in beta diversity between the two groups (all P < 0.05). Compared to the control group, Deferribacteres at phylum level, Roseburia, Ruminiclostridium, Anaerotruncus at genus level were significantly decreased in the AR group (all P < 0.05). Spearman's rank correlation showed that OVA-sIgE was positively correlated with Bacteroidetes, Muribaculaceae and Erysipelotrichaceae (all P < 0.05); IL-4 was significantly negatively correlated with Epsilonbacteraeota and Deferribacteres (all P < 0.05). Treg was significantly positively correlated with Patescibacteria, Lachnospiraceae, and Saccharimonadaceae in gut microecology. ConclusionOur results showed that the respiratory microbiota of AR mice was not significantly altered, but the gut microbiota varied significantly and there was a correlation between gut microbiota and Th1/Th2/Treg.

Analysis of nasopharyngeal microbiota revealing microbial disturbance associated with ovine respiratory complex

The ovine respiratory complex (ORC) is a complex respiratory disease process in ovine causing a significant health concern with substantial morbidity and mortality. It poses a significant threat of impacting animal health, leading to severe health consequences and considerable economic loss. Research on the upper respiratory tract (URT) microbiota is critical for offering insights into pathogenesis, prevention, and treatment strategies of ORC. The goal of this study is to compare the nasopharyngeal microbiota of clinically healthy Hu sheep (Group H) and sheep with ORC (Group P). The 16S rDNA gene amplicon high-throughput sequencing technique was applied to identify the microbial composition in the nasopharyngeal samples. The results showed that there was no significant difference in the microbiota diversity and richness between ORC and healthy sheep. However, there were significant differences in microbial composition, such as the relative abundance of Enterobacteriaceae, Moraxellaceae, Pasteurellaceae, and Streptococcaceae between the two groups. The abundance of aerobes in sheep with ORC increased significantly, while the abundance of anaerobes and facultative anaerobes decreased significantly. There were also differences in the taxa phenotypes associated with biofilm forming, mobile element-containing, oxidative stress-tolerance, and potential pathogens between the two groups. Our study showed the nasopharyngeal microbiota composition and its associated shifts between clinically healthy sheep and ORC sheep in China. These findings suggest that shifts in the nasopharyngeal microbiota could be a contributing factor to the pathogenesis of ORC, offering a potential avenue for the development of targeted interventions and treatments for this condition in sheep.

Oropharyngeal microbiome profiling and its association with age and heart failure in the elderly population from the northernmost province of China.

Respiratory tract infections are the most common triggers for heart failure in elderly people. The healthy respiratory commensal microbiota can prevent invasion by infectious pathogens and decrease the risk of respiratory tract infections. However, upper respiratory tract (URT) microbiome in the elderly is not well understood. To comprehend the profiles of URT microbiota in the elderly, and the link between the microbiome and heart failure, we investigated the oropharyngeal (OP) microbiome of these populations in Heilongjiang Province, located in the North-East of China, a high-latitude and cold area with a high prevalence of respiratory tract infection and heart failure. Taxonomy-based analysis showed that six dominant phyla were represented in the OP microbial profiles. Compared with young adults, the OP in the elderly exhibited a significantly different microbial community, mainly characterized by highly prevalent Streptococcus, unidentified_Saccharibacteria, Veillonella, unidentified_Pre votellaceae, and Neisseria. While unidentified_Prevotellaceae dominated in the young OP microbiome. There was competition for niche dominance between Streptococcus and member of Prevotellaceae in the OP. Correlation analysis revealed that the abundance of unidentified_Saccharibacteria was positive, while Streptococcus was negatively correlated to age among healthy elderly. The bacterial structure and abundance in the elderly with heart failure were much like healthy controls. Certain changes in microbial diversity indicated the potential OP microbial disorder in heart failure patients. These results presented here identify the respiratory tract core microbiota in high latitude and cold regions, and reveal the robustness of OP microbiome in the aged, supplying the basis for microbiome-targeted interventions.IMPORTANCETo date, we still lack available data on the oropharyngeal (OP) microbial communities in healthy populations, especially the elderly, in high latitude and cold regions. A better understanding of the significantly changed respiratory tract microbiota in aging can provide greater insight into characteristics of longevity and age-related diseases. In addition, determining the relationship between heart failure and OP microbiome may provide novel prevention and therapeutic strategies. Here, we compared OP microbiome in different age groups and elderly people with or without heart failure in northeastern China. We found that OP microbial communities are strongly linked to healthy aging. And the disease status of heart failure was not a powerful factor affecting OP microbiome. The findings may provide basic data to reveal respiratory bacterial signatures of individuals in a cold geographic region.

Host and environmental factors shape upper airway microbiota and respiratory health across the human lifespan

Our understanding of the normal variation in the upper respiratory tract (URT) microbiota across the human lifespan and how these relate to host, environment, and health is limited. We studied the microbiota of 3,104 saliva (<10 year-olds)/oropharynx (≥10 year-olds) and 2,485 nasopharynx samples of 3,160 Dutch individuals 0-87 years of age, participating in a cross-sectional population-wide study (PIENTER-3) using 16S-rRNA sequencing. The microbiota composition was strongly related to age, especially in the nasopharynx, with maturation occurring throughout childhood and adolescence. Clear niche- and age-specific associations were found between the microbiota composition and host/environmental factors and health outcomes. Among others, social interaction, sex, and season were associated with the nasopharyngeal microbial community. By contrast, the oral microbiota was more related to antibiotics, tobacco, and alcohol use. We present an atlas of the URT microbiota across the lifespan in association with environment and health, establishing a baseline for future research.

Gut and respiratory tract microbiota in children younger than 12 months hospitalized for bronchiolitis compared with healthy children: can we predict the severity and medium-term respiratory outcome?

Both the intestinal and respiratory microbiota of children with bronchiolitis, especially those with respiratory syncytial virus infection, are altered and differ from that of healthy children. The microbiota pattern in the acute episode could identify those children who will later have other respiratory episodes in the first year of life. Preventive measures could be adopted for this group of infants.

Analyzing the characteristics of respiratory microbiota after the placement of an airway stent for malignant central airway obstruction.

Malignant central airway stenosis is a life-threatening condition that can be effectively treated with airway stent placement. However, despite its clinical importance, the microbial characteristics of the respiratory tract following stent insertion remain poorly understood. This study addresses this gap by investigating the microbial features in patients with malignant central airway stenosis after stent placement, with a specific focus on microbial changes during granulation tissue proliferation. The findings reveal significant alterations in the diversity and structure of the respiratory tract microbiota following the placement of malignant central airway stents. Notably, certain bacterial species, including Peptostreptococcus stomatis and Achromobacter xylosoxidans, exhibit distinct patterns in the after-stent granulation tissue formation group. Additionally, the presence of tracheoesophageal fistula further influences the microbial composition. These insights provide valuable references for optimizing stent placement therapy and enhancing clinical anti-infective strategies.

Stenotrophomonas maltophilia contributes to smoking-related emphysema through IRF1-triggered PANoptosis of alveolar epithelial cells

Cigarette smoke (CS), the main source of indoor air pollution and the primary risk factor for respiratory diseases, contains chemicals that can perturb microbiota through antibiotic effects. Although smoking induces a disturbance of microbiota in the lower respiratory tract, whether and how it contributes to initiation or promotion of emphysema are not well clarified. Here, we demonstrated an aberrant microbiome in lung tissue of patients with smoking-related COPD. We found that Stenotrophomonas maltophilia (S. maltophilia) was expanded in lung tissue of patients with smoking-related COPD. We revealed that S. maltophilia drives PANoptosis in alveolar epithelial cells and represses formation of alveolar organoids through IRF1 (interferon regulatory factor 1). Mechanistically, IRF1 accelerated transcription of ZBP1 (Z-DNA Binding Protein 1) in S. maltophilia-infected alveolar epithelial cells. Elevated ZBP1 served as a component of the PANoptosome, which triggered PANoptosis in these cells. By using of alveolar organoids infected by S. maltophilia, we found that targeting of IRF1 mitigated S. maltophilia-induced injury of these organoids. Moreover, the expansion of S. maltophilia and the expression of IRF1 negatively correlated with the progression of emphysema. Thus, the present study provides insights into the mechanism of lung dysbiosis in smoking-related COPD, and presents a potential target for mitigation of COPD progression.

Microbiome features in bronchoalveolar lavage fluid of patients with idiopathic inflammatory myopathy-related interstitial lung disease.

Interstitial lung disease (ILD) is a common complication of idiopathic inflammatory myopathy (IIM), which is one of the connective tissue diseases (CTD). It can lead to poor prognosis and increased mortality. However, the distribution and role of the lower respiratory tract (LRT) microbiome in patients with IIM-ILD remains unclear. This study aimed to investigate the microbial diversity and community differences in bronchoalveolar lavage fluid (BALF) in patients with IIM-ILD. From 28 June 2021 to 26 December 2023, 51 individual BALF samples were enrolled, consisting of 20 patients with IIM-ILD, 16 patients with other CTD-ILD (including 8 patients with SLE and 8 with RA) and 15 patients with CAP. The structure and function of microbiota in BALF were identified by metagenomic next-generation sequencing (mNGS). The community evenness of LRT microbiota within the IIM-ILD group was marginally lower compared to the other CTD-ILD and CAP groups. Nonetheless, there were no noticeable differences. The species community structure was similar among the three groups, based on the Bray-Curtis distance between the samples. At the level of genus, the IIM-ILD group displayed a considerably higher abundance of Pseudomonas and Corynebacterium in comparison to the CAP group (p < 0.01, p < 0.05). At the species level, we found that the relative abundance of Pseudomonas aeruginosa increased significantly in the IIM-ILD group compared to the CAP group (p < 0.05). Additionally, the relative abundance of Prevotella pallens was significantly higher in other CTD-ILD groups compared to that in the IIM-ILD group (p < 0.05). Of all the clinical indicators examined in the correlation analysis, ferritin level demonstrated the strongest association with LRT flora, followed by Serum interleukin-6 level (p < 0.05). Our research has identified particular LRT microorganisms that were found to be altered in the IIM-ILD group and were significantly associated with immune function and inflammatory markers in patients. The lower respiratory tract microbiota has potential in the diagnosis and treatment of IIM-ILD.

Study of the spectrum and antibiotic sensitivity of the respiratory tract microbiota of newborns with infectious complications during long-term mechanical lung ventilation

determining the structure of leading microbial colonizers of the respiratory tract as potential causative agents of ventilator-associated pneumonia and their sensitivity to antibacterial drugs plays an important role in choosing effective tactics for etiotropic therapy of newborns. According to the data of scientific publications, the etiological structure of infectious complications associated with long-term respiratory support in newborns is known to have certain features. The spectrum of nosocomial microbial pathogens and their sensitivity to antimicrobial drugs are among them. The patients of early age are characterized by a number of peculiarities of anatomical and physiological characteristics and the qualitative and quantitative composition of the microbiota of the respiratory tract. In order to form ideas about the determining causative agents of VAP in newborns, it was advisable to conduct a microbiological study of the species composition of microorganisms associated with this infectious complication, as well as to determine their sensitivity to antibiotics recommended by the management protocols of the corresponding pathology. To study and solve this problem, it is necessary to study the spectrum and antibiotic sensitivity of the causative agents of VAP. A prospective study was conducted in 69 newborns with VAP (2020 - 2023), who were treated in the Neonatal Intensive Care Unit (NICU) of the Vinnytsia Regional Children's Clinical Hospital (VRCCH) and consisted in studying the composition of the microbiota and antibiotic sensitivity. We took into account opportunistic microorganisms that are not characteristic of this biotope of the respiratory tract of newborns who were diagnosed with VAP during long-term mechanical ventilation. As a result of the prospective analysis of the microbiological study of the microbiota of 69 newborns, 82 microorganisms - etiologically significant pathogens of VAP - were isolated and identified. Thus, according to the data of our bacteriological studies, 17 Gram-positive and 65 Gram-negative pathogens of VAP were isolated and identified in NICU VRCCH for 2020-2023. As a result of the study of antibiotic sensitivity of VAP pathogens in newborns, the following trends were observed. Low sensitivity of Acinetobacter baumannii to ceftazidime, aztreonam, imipinem, meropenem, amoxicillin, piperacillin, levofloxacin, ciprofloxacin was established. And sensitive to amikacin, gentamicin and cefoperazone-sulbactam. High rates of resistance of Pseudomonas aeruginosa to ceftazidime, doxycycline, imipinem, meropenem, gentamicin, piperacillin, levofloxacin, ciprofloxacin, ofloxacin were established. The best indicators of sensitivity of P. aeruginosa to amikacin, cefoperazone-sulbactam and tobramycin were found. According to the results of the sensitivity of K. pneumoniae to antibiotics, resistance to all antibiotics was established. The development of resistance of Staphylococcus aureus to azithromycin, norfloxacin, cefotaxime, benzylpenicillin has been established. The indicators of S. aureus sensitivity to amikacin, tetracycline and vancomycin turned out to be the best. We took into account opportunistic microorganisms that are not typical for this biotype of the airways of newborns who were diagnosed with VAP during long-term mechanical ventilation. The results of the study indicate the need to take into account the data of a microbiological study with the mandatory identification of isolated pathogens, their microbial load at the site of infection, determining their antibiotic sensitivity is of crucial importance in the selection of etiotropic treatment tactics for newborns with VAP.

Neurocognitive disorders and chronic rhinosinusitis. A modern view of the problem (literary review)

The purpose of the study: to review the results of scientific research on combined etiopathogenetic, clinical, and functional manifestations of chronic rhinosinusitis and a number of neurological diseases classified as neurocognitive disorders (NCDs). The interdisciplinary approach in the analysis was based on the modern understanding of neurocognitive disorders and induced neuroinflammatory reactions, the commonality between the infectious agents in the pathogenesis of chronic rhinosinusitis and diseases characterized by NCDs, and the validity of the involvement of central brain structures in the process of chronic inflammation of the nasal cavity and paranasal sinuses. The analogy of the formation of such manifestations as nasal obstruction, changes in the olfactory tract and visual function, and disorders of the microbiota of the upper respiratory tract, and their impact on brain structures with impaired neurocognitive functions was drawn. The systematization of scientific research data characterizing various chronic forms of rhinosinusitis and NCDs was a confirmation of the regulatory role of the autonomic nervous system and the hypothalamic-limbic-reticular complex in understanding the common pathophysiological mechanisms occurring in these nosologies.

Evaluation of clinical characteristics and risk factors associated with Chlamydia psittaci infection based on metagenomic next-generation sequencing

IntroductionPsittacosis is a zoonosis caused by Chlamydia psittaci, the clinical manifestations of Psittacosis range from mild illness to fulminant severe pneumonia with multiple organ failure. This study aimed to evaluate the clinical characteristics of Chlamydia psittaci infection diagnosed based on metagenomic next-generation sequencing(mNGS), as well as the risk factors affecting the progress of Chlamydia psittaci infection, in order to improve the effect of therapeutics.MethodsWe retrospectively analyzed the clinical data of patients infected with chlamydia psittaci in the First Affiliated Hospital of Nanchang University from January 2021 to December 2021. The patient’s past medical history, clinical manifestations, laboratory examinations, chest CT results, treatment status, and prognosis data were collected. we also investigated both the pathogenic profile characteristics and the lower respiratory tract microbiota of patients with Chlamydia psittaci pneumonia using mNGS.ResultsAll cases of Chlamydia psittaci in our research have been confirmed by mNGS. Among 46 cases of Chlamydia psittaci pneumonia, Poultry exposure was reported in 35 cases. In severe cases of Chlamydia psittaci pneumonia, Neutrophils, Procalcitonin (PCT), Lactate Dehydrogenase (LDH), Hydroxybutyrate Dehydrogenase (HBDH), Creatine Kinase Isoenzymes-B (CK-MB) and D-Dimer levels were remarkably higher than that of non-severe cases, except for lymphocytes (all P < 0.05). Chest CT scans showed Bilateral (77.8%), multiple lobar lungs (85.2%), pleural effusions (44.4%) involvement in those suffering from severe Chlamydia psittaci pneumonia, whereas its incidence was 0%, 21.1% and 10.5% in non-severe patients, respectively (P < 0.05). Multivariate analysis revealed that higher lymphocyte concentrations (OR 0.836, 95% CI 0.714–0.962, P = 0.041) were the only protective factor for survival. mNGS results indicated that 41.3% of patients (19/46) had suspected coinfections with a coinfection rate of 84.2% (16/19) in the severe group, much higher than that in the non severe group (p < 0.05). No significantly different profiles of lower respiratory tract microbiota diversity were found between non severe group and severe group.ConclusionA history of poultry exposure in patients can serve as an important basis for diagnosing Chlamydia psittaci pneumonia, and patients with severe Chlamydia psittaci pneumonia are more likely to develop elevated inflammatory biomarkers as well as elevated cardiac markers. Higher lymphocyte concentrations are protective factors associated with severe C. psittaci pneumonia. The higher proportion of patients with coinfections in our study supports the use of mNGS for comprehensive early detection of respiratory infections in patients with C. psittaci pneumonia.

Yinhuang buccal tablet alters airway microbiota composition and metabolite profile in healthy humans

Ethnopharmacological relevancePerturbations in airway microbiota composition and disruption of microbe-metabolite interactions have been observed in respiratory infectious diseases (RIDs). The Yinhuang (YH) buccal tablet, as an ancient Chinese medicinal formula, has been traditionally employed for the management of upper RIDs. However, there is a lack of evidence for the effects of YH buccal tablets on upper respiratory tract microbiota and circulating metabolites. Aim of the studyThe aim of this study was to analyze the changes in respiratory microbiota composition and circulating metabolite profile after YH buccal tablets administration. Materials and methodsThroat swab samples and serum samples were collected from 60 healthy subjects for high-throughput 16S ribosomal RNA gene (16S rRNA) sequencing and non-targeted Ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. ResultsAirway microbial composition changed significantly after YH administration. The abundance of Actinomyces and Prevotella_7 increased, while the abundance of potentially pathogenic Pseudomonas and Corynebacterium decreased. A total of 168 significant HMDB taxonomic metabolites were identified in serum samples, of which lipid metabolites accounted for the largest proportion. Correlation analysis showed that circulatory metabolites were significantly correlated with changes in airway microbiota composition. ConclusionsYH buccal tablets can inhibit opportunistic pathogens, increase beneficial microorganisms in the upper respiratory tract, and regulate the body's metabolic pathways. These findings provide insights into the mechanism of action of YH buccal tablets in the treatment and prevention of respiratory diseases.

Microbiota of the upper respiratory tract in children with chronic adenoiditis

Background. Routine application of the GC-MS method to assess the URT microbiota can potentially improve the efficacy and safety of treatment for chronic respiratory diseases.&#x0D; Aim. To perform a comparative analysis of the microbiota from the surface of the pharyngeal tonsil, from the deep parts of the nose, and saliva in children with chronic adenoiditis.&#x0D; Materials and methods. The study included 90 patients with chronic adenoiditis (CA) and/or pharyngeal tonsil hypertrophy (PTH). All study participants had swabs taken from the surface of the pharyngeal tonsil, from the deep parts of the nasal cavity, and saliva as a biological fluid of the oral cavity. Microorganisms were identified by specific fatty acids using GC-MS to assess the composition of the microbial community on the surface of the pharyngeal tonsil.&#x0D; Results. The study showed that the microbiota of the nasopharynx is identical in its qualitative composition to microorganisms from the deep parts of the nose. However, according to the results of the analysis of microbial markers of saliva, the oral microbiota showed significant differences in the quantitative and qualitative composition of microorganisms compared with the nasopharyngeal microbiota.&#x0D; Conclusion. The introduction of the GC-MS method for assessing the URT microbiota enables its monitoring in clinical practice for the treatment of chronic respiratory system diseases without disturbing the ecology of the mucous membranes and the whole body.

Baicalin Protects Broilers against Avian Coronavirus Infection via Regulating Respiratory Tract Microbiota and Amino Acid Metabolism.

An increasing amount of evidence indicates that Baicalin (Bai, a natural glycosyloxyflavone compound) exhibits an antiviral effect against avian viruses. However, it remains unclear if the antiviral effect of Bai against infectious bronchitis virus (IBV) is exerted indirectly by modulating respiratory tract microbiota and/or their metabolites. In this study, we investigated the protection efficacy of Bai in protecting cell cultures and broilers from IBV infection and assessed modulation of respiratory tract microbiota and metabolites during infection. Bai was administered orally to broilers by being mixed in with drinking water for seven days. Ultimately, broilers were challenged with live IBV. The results showed that Bai treatment reduced respiratory tract symptoms, improved weight gain, slowed histopathological damage, reduced virus loads and decreased pro-inflammation cytokines production. Western blot analysis demonstrated that Bai treatment significantly inhibited Toll-like receptor 7 (TLR7), myeloid differentiation factor 88 (MyD88) and nuclear factor kappa-B (NF-κB) expression both in cell culture and cells of the trachea. Bai treatment reversed respiratory tract microbiota dysbiosis, as shown by 16S rDNA sequencing in the group of broilers inoculated with IBV. Indeed, we observed a decrease in Proteobacteria abundance and an increase in Firmicutes abundance. Metabolomics results suggest that the pentose phosphate pathway, amino acid and nicotinamide metabolism are linked to the protection conferred by Bai against IBV infection. In conclusion, these results indicated that further assessment of anti-IBV strategies based on Bai would likely result in the development of antiviral molecule(s) which can be administered by being mixed with feed or water.

Symbiotic microbial communities in various locations of the lung cancer respiratory tract along with potential host immunological processes affected.

Lung cancer has the highest mortality rate among all cancers worldwide. The 5-year overall survival rate for non-small cell lung cancer (NSCLC) is estimated at around 26%, whereas for small cell lung cancer (SCLC), the survival rate is only approximately 7%. This disease places a significant financial and psychological burden on individuals worldwide. The symbiotic microbiota in the human body has been significantly associated with the occurrence, progression, and prognosis of various diseases, such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis. Studies have demonstrated that respiratory symbiotic microorganisms and their metabolites play a crucial role in modulating immune function and contributing to the pathophysiology of lung cancer through their interactions with the host. In this review, we provide a comprehensive overview of the microbial characteristics associated with lung cancer, with a focus on the respiratory tract microbiota from different locations, including saliva, sputum, bronchoalveolar lavage fluid (BALF), bronchial brush samples, and tissue. We describe the respiratory tract microbiota's biodiversity characteristics by anatomical region, elucidating distinct pathological features, staging, metastasis, host chromosomal mutations, immune therapies, and the differentiated symbiotic microbiota under the influence of environmental factors. Our exploration investigates the intrinsic mechanisms linking the microbiota and its host. Furthermore, we have also provided a comprehensive review of the immune mechanisms by which microbiota are implicated in the development of lung cancer. Dysbiosis of the respiratory microbiota can promote or inhibit tumor progression through various mechanisms, including DNA damage and genomic instability, activation and regulation of the innate and adaptive immune systems, and stimulation of epithelial cells leading to the upregulation of carcinogenesis-related pathways.

Quantitative and species changes in the local microbiota of the upper respiratory tract in allergic rhinitis

BACKGROUND: The role of local microflora in the pathogenesis of allergic rhinitis has not been sufficiently studied; therefore, the study of changes in the nasal microbiome is of interest from a scientific and practical point of view.&#x0D; AIM: To evaluate changes in the local microbiota of the nasal mucosa in patients with seasonal and year-round allergic rhinitis before and after pharmacological and allergen-specific therapy.&#x0D; MATERIALS AND METHODS: An observational retrospective single-center case-control study was conducted, which included 182 patients with allergic rhinitis. The groups were randomized according to the diagnosis (seasonal and year-round allergic rhinitis) and the therapy used: basic pharmacotherapy and allergen-specific (sublingual) immunotherapy.&#x0D; RESULTS: In total, 182 patients completed the study, of which 50 had seasonal allergic rhinitis, 51 had seasonal allergic rhinitis + atopic asthma (aged 7–42 years), and 81 had year-round allergic rhinitis, which included 29 aged 12–54 years and 52 with year-round allergic rhinitis + atopic asthma, aged 12–39 years. Patients with allergic rhinitis were divided into two subgroups: those who received basic therapy to achieve remission and those who received allergen-specific (sublingual) immunotherapy. After basic therapy, the abundance of Staphylococcus aureus in the local microbiota of the upper respiratory tract in patients with seasonal allergic rhinitis decreased by 1.4 times; in the allergen-specific (sublingual) immunotherapy group, its abundance more significantly decreased (3.9 times; p 0.05). In the group with year-round allergic rhinitis, the same pattern was noted. In the group with seasonal allergic rhinitis and year-round allergic rhinitis and the group with both allergen-specific (sublingual) immunotherapy and atopic asthma who received a full course of allergen-specific (sublingual) immunotherapy, the activation index of blood basophils by rSplA-proteinase S. aureus was reduced by 1.2–1.5 compared with the value in those who received basic pharmacotherapy.&#x0D; CONCLUSION: Patients with allergic rhinitis exhibited quantitative and qualitative significant changes in the microbiome of the upper respiratory tract mucosa, one of the consequences of which is the development of IgE-mediated sensitization to S. aureus products. Allergen-specific immunotherapy for patients with allergic rhinitis leads to decreased colonization of the nasal mucosa with S. aureus and decreased sensitization to rSplA proteinase.