Search Results (78)

Background: Chronic rhinosinusitis (CRS) and obstructive sleep apnea (OSA) frequently coexist, sharing inflammatory and anatomical pathways consistent with the “United Airway”. This review examines the synergistic dysfunction linking these conditions. Methods: We conducted a narrative review synthesizing literature on the epidemiology, pathophysiology—including cytokine cascades and microbiome dysbiosis—and therapeutic outcomes of surgical and medical interventions for comorbid CRS and OSA. Results: Large-scale datasets confirm CRS as an independent risk factor for OSA. Pathophysiologically, the disorders are linked by mechanical obstruction, systemic cytokine spillover (IL-6, TNF-a), and nasopharyngeal microbiome dysbiosis (e.g., S. aureus biofilms). Therapeutically, Endoscopic Sinus Surgery (ESS) significantly improves subjective sleep quality (SNOT-22) and reduces CPAP pressure requirements, although it yields only trivial reductions in the Apnea-Hypopnea Index (AHI). Biologics like Dupilumab demonstrate rapid efficacy in improving sleep domains for CRS with nasal polyps. Conclusions: CRS and OSA are inextricably linked via mechanical and inflammatory mechanisms. A holistic “United Airway” management approach—optimizing nasal patency to facilitate CPAP adherence and reduce systemic inflammatory burden—is critical for improving patient outcomes. Full article

Background/Objectives: Asthma affects millions of patients worldwide and impacts their quality of life, particularly among children. Colonisation or an imbalance within natural resident microbiota may drive inflammatory responses in asthma; antibiotic resistance genes (ARGs) have also been investigated in asthma microbiome studies. However, research on the association between airway microbiota and ARGs remains limited. Therefore, we elucidated functional-level characterisation at the level of ARGs, virulence factors, and active pathways among a paediatric asthma cohort relative to a healthy control. Methods: Overall, 29 children with asthma and 20 control subjects were enrolled, and 3 swabs (2 nasal and 1 oropharyngeal) were obtained from each participant. Genomic DNA was extracted and sent for shotgun sequencing, after which bioinformatic analysis was conducted to remove human reads and analyse the microbiota pattern in the samples. The abundance of antibiotic resistance genes was evaluated along with the distribution of virulence genetic markers. Functional investigation of the most prevalent metabolic pathways was also performed. Results: Upper airway microbiome functional capacity varied by anatomical location, with oropharyngeal communities exhibiting greater metabolic breadth than nasal communities, suggesting the sample source to be the dominant factor shaping gene content, pathway profiles, and community structure. Asthma-related functional differences were modest, and no biological pathways remained significant following false discovery rate correction. Enrichment of antimicrobial resistance genes was observed, particularly those conferring resistance to β-lactams, macrolides, and tetracyclines. Conclusions: Different anatomical niches exhibit differential activities, and further exploration in this direction could aid in the development of diagnostic and therapeutic biomarkers for asthma. Full article

Chronic rhinosinusitis (CRS) is a persistent inflammatory disorder of the nasal and paranasal mucosa, typically attributed to local infection or anatomical obstruction. However, recent evidence suggests that CRS may also reflect systemic inflammatory dysregulation influenced by the gut microbiome, establishing a potential ‘gut–sinus axis’. This systematic review aims to synthesise current evidence linking gut microbiome alterations to the pathogenesis and clinical course of CRS and to explore emerging therapeutic strategies targeting this axis. Five databases were comprehensively searched for studies published between January 2000 and October 2025. Data were extracted and evaluated for quality using the JBI and SYRCLE tools. A total of 441 records were retrieved, of which 20 studies met the inclusion criteria. Human studies consistently showed gut dysbiosis in CRS, characterised by reductions in Roseburia, Bifidobacterium, Faecalibacterium and Akkermansia species. These microbial shifts correlated with increased levels of systemic cytokines, such as interleukin-6, interleukin-17 and tumour necrosis factor-α, and disease severity. Animal and interventional studies confirmed that high-fibre diets and short-chain fatty acid (SCFA) supplementation modified airway inflammation, whereas antibiotic-induced dysbiosis exacerbated it. Current evidence substantiates a gut–sinus axis mediated by immune, metabolic and neuroendocrine pathways. Dysbiosis-driven reductions in SCFA-producing bacteria appear central to systemic pro-inflammatory signalling implicated in CRS. Full article

Chronic rhinosinusitis (CRS) is a heterogeneous inflammatory disease of the nasal and paranasal sinus mucosa with substantial impact on quality of life. Although atopy and/or allergic rhinitis frequently coexist with CRS, often alongside type 2-skewed inflammation, the extent to which allergic mechanisms define a discrete CRS entity remains debated, in part due to inconsistent operational definitions and overlapping clinical phenotypes. In parallel, culture-independent sequencing studies have reframed CRS as a disorder of host–microbe interactions, with many cohorts reporting reduced sinonasal microbial diversity, enrichment of potentially pathogen taxa (including Staphylococcus aureus), and biofilm-associated community states. However, causality and directionality remain uncertain. In this narrative review, we synthesize evidence at the interface of epithelial barrier dysfunction, type 2 cytokine networks (IL-4/IL-13/IL-5), and microbiome dysbiosis, highlighting where data are consistent across studies versus where findings are heterogeneous or predominantly associative. We discuss representative allergy-associated CRS prototypes such as allergic fungal rhinosinusitis and central compartment atopic disease as clinical models to interrogate these interactions, while distinguishing them from non–IgE-mediated type 2 entities such as aspirin-exacerbated respiratory disease. We also summarize current data linking atopy to sinonasal microbial signatures and discuss emerging microbiome-directed interventions (topical probiotics, bacteriophages, and microbiota transfer concepts) alongside biologics and precision anti-inflammatory therapies. Finally, we highlight key knowledge gaps, including the limited endotype-resolved and longitudinal studies, variable allergic phenotyping in microbiome research, and the need for standardized definitions and biomarker-driven stratification to clarify clinical utility and to guide mechanism-informed therapeutic trials. Full article

Dogs show exceptional olfactory sensitivity and are widely used in medical, rescue, military, and forensic applications, yet the determinants of individual and breed-level scent-work performance remain incompletely characterized. This review integrates evidence from the anatomy and physiology of the canine olfactory organ, neurobiological mechanisms of odor transduction and coding, and links between olfaction, memory, and emotion, alongside molecular genetics, evolution, domestication, and selective breeding. We synthesize findings indicating that complex nasal turbinates and specialized airflow patterns enhance odorant capture, while olfactory bulb circuitry and downstream connections to limbic and frontal networks support discrimination, learning, and affective modulation. Comparative and breed-focused studies suggest that skull morphology and breeding priorities can alter olfactory capacity, with shortened nasal anatomy associated with reduced functional potential in some lines. In applied contexts, detection success is strongly shaped by behavioral traits such as motivation, persistence, independence, and reward value, as well as by physical condition and environmental stressors that can impair search efficiency. Emerging literature further suggests that the gastrointestinal and upper airway microbiome, together with diet, housing, temperature, and workload, may influence sensory and cognitive readiness, although direct causal links to detection outcomes remain limited. Overall, canine olfactory performance reflects interactions among genetic–anatomical capacity, neurobehavioral factors, and environment, underscoring the value of standardized selection, training, welfare management, and future integrative research. Full article

The nasal microbiome represents a complex and dynamic microbial ecosystem that contributes to mucosal defense, epithelial homeostasis, immune regulation, and olfactory function. Increasing evidence indicates that this microbial community actively interacts with host physiology, while alterations in its composition are associated with chronic inflammation, oxidative stress, and olfactory impairment. Such changes have been reported in conditions including chronic rhinosinusitis, allergic rhinitis, and post-viral anosmia. Beyond local effects, chronic nasal inflammation has been hypothesized to influence neuroinflammatory processes and protein aggregation pathways involving α-synuclein and tau, potentially linking nasal microbial imbalance to neurodegenerative mechanisms. However, current evidence remains largely indirect and does not support a causal relationship. This narrative review summarizes current clinical and immunological evidence on the role of the nasal microbiome in olfactory function and dysfunction, highlighting limitations of existing studies and outlining future research directions. Full article

Background: Although diabetes mellitus is traditionally viewed as a systemic metabolic disorder, growing evidence indicates that it also affects the upper airways through vascular, inflammatory, and neuro-sensory mechanisms. The sinonasal mucosa, highly vascularized and immunologically active, may represent an early target of diabetic microangiopathy and immune–metabolic imbalance. Objectives: Our objectives are to synthesize current evidence on the rhinologic manifestations of DM, with a focus on chronic rhinosinusitis, olfactory dysfunction, and other nasal disorders, and to identify the main pathophysiologic and clinical patterns linking diabetes to sinonasal disease. Results: Evidence suggests that DM, particularly type 2 DM, increases susceptibility to CRSwNP and modulates the sinonasal microbiome toward Gram-negative predominance. Surgical outcomes after endoscopic sinus surgery are generally comparable between diabetics and non-diabetics when perioperative care is optimized. Olfactory dysfunction occurs more frequently and severely in diabetic patients, likely reflecting the combined effects of chronic inflammation, vascular compromise, and insulin resistance. Additional manifestations include recurrent epistaxis, delayed mucociliary clearance, and chronic cough. Allergic rhinitis appears to not be increased, and maybe even inversely related, especially among users of DPP-4 inhibitors. Conclusions: Diabetes intersects with rhinologic health through immune–metabolic, vascular, and epithelial pathways that may shape susceptibility, disease phenotype, and neurosensory decline. Future research should focus on disentangling type-specific mechanisms, metabolic biomarkers, and longitudinal outcomes, with the aim of developing precision-based approaches to rhinologic assessment and management in diabetic patients. Full article

Allergic rhinitis (AR) is a common heterogeneous chronic disease characterized by high prevalence, complex pathogenesis, and susceptibility to multiple contributing factors. Currently, its prevalence ranges from 20% to 30% in adults and reaches up to 40% in children. Extensive research has confirmed significant differences in nasal microbiota composition between AR patients and healthy individuals, most notably alterations in the abundance of four dominant phyla: Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. Among these, the most striking abundance alterations occur in Staphylococcus aureus and Streptococcus salivarius within the nasal mucosa of AR patients, suggesting a critical role of nasal microbiota in AR initiation and progression. In response, researchers have proposed microbiome-targeted therapeutic strategies. For example, nasal local administration of probiotics (e.g., Lactobacillus and Bifidobacterium) aims to reshape the nasal microbiota. Additionally, protective bacteria such as Corynebacterium accolens and Dolosigranulum pigrum can inhibit pathogenic bacteria, thereby correcting microbial dysbiosis and alleviating AR symptoms. This review summarizes the composition of the nasal microbiota, the latest research progress on its association with AR, and the underlying potential mechanisms. It provides novel insights and potential therapeutic strategies for the prevention and treatment of AR. Full article

Background: Chronic rhinosinusitis (CRS) affects nearly 9% of the global population with a rising incidence over recent decades. Neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease pose significant global burden, and emerging evidence suggests pathophysiological links through shared bioenergetic dysfunction, peripheral-to-central inflammatory signaling, and altered nasal microbiota. This review evaluates the evidence for CRS as a potentially modifiable peripheral contributor to neurodegenerative disease progression. Methods: A systematic review was conducted using PubMed, Cochrane, Web of Science, Embase, and CENTRAL from January 2000 to July 2025. Search terms included “Chronic Rhinosinusitis,” “Neurodegeneration,” “Mild Cognitive Impairment,” “Alzheimer’s Disease,” “Parkinson’s Disease,” “Bioenergetics,” and “Microbiome.” Clinical and experimental studies exploring epidemiological links, mechanistic pathways, biomarkers, and therapeutic targets were included. Results: Twenty-one studies involving over 100,000 participants met the inclusion criteria. Existing meta-analytic evidence demonstrated significant associations between CRS and cognitive impairment, with patients scoring approximately 9% lower on global cognitive measures than controls. However, other large-scale cohort studies did not pinpoint an increased dementia incidence, suggesting CRS may contribute to early, potentially reversible cognitive decline without directly driving dementia onset. Neuroimaging studies revealed altered frontoparietal connectivity and orbitofrontal hyperactivity in CRS patients. Mechanistic studies support peripheral inflammatory cytokines disrupting the blood–brain barrier, autonomic dysfunction impairing mucociliary clearance, microbiome-driven amyloid cross-seeding, and compromised cerebrospinal fluid clearance via olfactory–cribriform pathways. Discussion: Evidence supports complex, bidirectional relationships between CRS and neurodegeneration characterized by convergent inflammatory, autonomic, and bioenergetic pathways. Therapeutic strategies targeting sinonasal inflammation, microbiome dysbiosis, and mitochondrial dysfunction represent promising intervention avenues. Recognizing CRS as a treatable factor in neurodegenerative risk stratification may enable earlier diagnosis and prevention strategies. Full article

This study represents the first investigation into the prevalence of pathogenic bacteria in isolated, free-ranging Eastern Grey Kangaroos (Macropus giganteus) inhabiting a human-shared environment. Samples were collected from the nasal and rectal passages of state-authorised culls of M. giganteus within a military training area, where recruits had reported recurrent cases of skin and soft tissue infections. The objective was to identify clinically relevant pathogenic microorganisms present in the nasal and rectal flora of these kangaroos. Analysis revealed carriage rates of 11% for methicillin-sensitive Staphylococcus aureus (MSSA) and 2% for methicillin-resistant S. aureus (MRSA). Other potentially pathogenic bacteria isolated included Pseudomonas spp., Streptococcus (Groups B and D), Acinetobacter spp., and multiple coagulase-negative Staphylococcus (CoNS) species. Notably, CoNS species were present in 17% of nasal isolates, with Mammaliicoccus sciuri (formerly Staphylococcus sciuri) detected in 41% of these isolates, suggesting a potential reservoir for antibiotic resistance genes and virulence factors. These findings support a One Health perspective, highlighting the interconnectedness of pathogenic bacteria, M. giganteus, humans, and their shared environment. Full article

Bovine respiratory disease complex (BRDC) is a leading cause of morbidity and mortality in pre-weaned calves, yet the role of commensal nasal microbiota in outbreak severity remains poorly understood. This study characterized nasal bacterial communities during two BRDC outbreaks of differing severity (moderate vs. severe) and at ~30 days post-treatment. Nasal swabs were collected from calves and analyzed using 16S rRNA gene sequencing (V1–V3 regions, Illumina MiSeq) and quantitative PCR targeting three major BRDC pathogens. Microbial community profiles differed between outbreak groups and across timepoints. Calves in the severe outbreak group exhibited lower microbial diversity compared to those in the moderate outbreak. In both groups, diversity significantly increased from outbreak to post-treatment. At the time of disease, nasal communities were dominated by the genera Mycoplasmopsis, Mesomycoplasma, and Caviibacter, with qPCR confirming Mycoplasma bovirhinis as the predominant species. These findings indicate that BRDC outbreaks in pre-weaned calves are associated with reduced microbial diversity and the dominance of pathogenic Mycoplasma species, with recovery characterized by greater bacterial diversity. Shifts in nasal microbiome composition between outbreak and post-treatment may reflect pathogen-driven disruption during disease and subsequent microbial community rebalancing. Full article

A systematic review was conducted to assess the effects of microgravity and space radiation on astronauts’ oral health. This review aimed to determine if these conditions increase the risk of dental and periodontal diseases, identify pre-mission dental care strategies, and specify relevant dental emergencies for astronauts to manage during missions. Following PRISMA guidelines, the review was registered on PROSPERO (CRD42023472765). Databases including PubMed, Scopus, Web of Science, Cochrane Library, and OVID Medline were searched. Of the 13 studies identified, 7 were eligible for qualitative synthesis. The included studies revealed that space conditions compromise oral health. Findings indicate changes in saliva composition, with a significant decline in salivary lysozyme levels during missions lasting 28 to 84 days. Salivary IgA levels also increased before and peaked after flights (microgravity alters fluid shear and protein folding). Viral reactivation was a key finding, with latent viruses such as Epstein–Barr virus (EBV), cytomegalovirus (CMV), and varicella zoster virus (VZV) being reactivated during missions (immune suppression and gene expression shifts under spaceflight stress). Data from a study found that 50% of crew members shed viruses in their saliva or urine, and 38% tested positive for herpesviruses. The included studies also documented alterations in the oral microbiome, including increased gastrointestinal and decreased nasal microbial diversity. This suggests alterations in salivary biomarkers, viral shedding, and microbiome changes in astronauts during long-duration missions. These changes appear associated with immune dysregulation and stress, but causality remains uncertain due to observational designs, small heterogeneous samples, and confounding factors. Although current evidence is indicative rather than definitive, these findings highlight the need for preventive dental measures prior to missions and preparedness for managing oral emergencies in-flight. Future studies should address the mechanistic separation of microgravity and radiation effects, with implications for upcoming Moon and Mars missions. Full article

Background/Objectives: In this study, we aimed to evaluate probiotics’ clinical efficacy and safety in adults with chronic rhinosinusitis (CRS), and summarize mechanistic evidence related to mucosal immunity and microbiota modulation. Methods: We performed a systematic review and random-effects meta-analysis. MEDLINE, Embase, Scopus, Web of Science, and the Cochrane Library were searched until May 2025. Eligibility: Randomized controlled trials (RCTs) and mechanistic studies investigating probiotics (any strain, dose, or administration route) in adults with CRS were eligible. Primary outcomes included changes in Sino-Nasal Outcome Test (SNOT-20/22) scores and CRS relapse rates. Secondary outcomes were adverse events and mechanistic endpoints. Results: Six studies (four RCTs, n = 337; two mechanistic studies) met the inclusion criteria. Probiotics did not significantly improve SNOT scores compared with the placebo, but trended in that direction (pooled mean difference—2.70; 95% CI −7.12 to 1.72; I² = 0%). Furthermore, probiotic use was associated with a non-significant trend towards fewer CRS relapses (risk ratio 0.41; 95% CI 0.16–1.04; p = 0.06; I² = 48%). Adverse events were mild and comparable to the placebo (risk ratio 0.87; 95% CI 0.33–2.34). Mechanistic data indicated that intranasal Lactococcus lactis W136 might downregulate type 1 inflammatory pathways and modestly increase microbiome diversity. Subgroup analyses (by route, duration, and CRS subtype) revealed no statistically significant effect modifiers, though mechanistic insights suggest possible differences in efficacy based on the CRS endotype and delivery method. Conclusions: Probiotics appear safe and may provide a small, non-significant improvement in CRS symptoms; emerging evidence of reduced relapse rates warrants further investigation through larger, endotype-stratified trials utilizing targeted probiotic strains and optimized delivery methods. Full article

The equine respiratory and reproductive tract microbiomes are complex and subject to constant fluctuations. Among the microbial inhabitants, Streptococcus equi subsp. zooepidemicus (SEZ) is recognized as the dominant bacterium. It is an opportunistic pathogen that may occasionally lead to various types of infections. A key virulence factor of SEZ is the streptolysin S (SLS) toxin, which is responsible for the characteristic β-hemolysis on blood agar and tissue damage. Viruses and bacteria may interact and aggravate lesions and disease. This study aimed to evaluate the impact of an SLS-containing supernatant from SEZ on the nasal and vaginal mucosa and the subsequent replication of equine herpesviruses. The SLS-containing supernatant was prepared, and three 10-fold dilutions (optical density “OD” 10⁻², 10⁻³, 10⁻⁴) were applied to equine nasal and vaginal explants. Untreated and EGTA-treated explants served as controls. Epithelial integrity was assessed by measuring the thickness and intercellular spaces. Nasal explants were inoculated with EHV-1 and EHV-4, while vaginal explants received EHV-1 and EHV-3. Viral replication was estimated via immunofluorescence staining and confocal microscopy. SLS-containing supernatants 10⁻² and 10⁻³ compromised epithelial integrity. Viral replication increased in explants treated with SLS 10⁻³, demonstrating SLS’s damaging effects on the epithelium, facilitating equine herpesvirus replication. Full article

Background: Functional endoscopic sinus surgery (FESS) is the treatment of choice for medically refractory CRS. However, the success rate of FESS is dependent on both baseline medical and demographic characteristics. Consequently, we performed an analysis of systemic/nasal cytokines and the sinus microbiome to assess their impact on the SNOT-22 response after functional endoscopic sinus surgery (FESS). Methods: A prospective observational study was performed on 44 patients with chronic rhinosinusitis undergoing FESS between December 2021 and September 2022. Diseased sinus tissue from 25 patients was subjected to whole-exome sequencing (WES) for taxonomical profiling of the sinus bacterial composition. Additional data collection included demographics, comorbidities, baseline sinonasal outcome test scores, post-operative sinonasal outcome test scores (at 3–4 months), and nasal/systemic cytokines. Results: Our analysis demonstrated that CRSwNP patients in the surgical responder cohort had statistically significantly higher median [P25, P75] levels of intra-nasal IL-5, indicating type 2 sinonasal disease (63 pg/μL [28, 118] versus 17 pg/μL [16.6, 18], p = 0.04). At the genus level, the relative abundance of Staphylococcus was significantly higher in the surgical non-responder cohort compared to the responder group. An ROC curve was highly accurate at distinguishing responders versus non-responders to FESS based on a microbiota-based random forest model (AUC = 0.92). Conclusions: Intra-nasal IL-5 levels and the bacterial composition of the sinus microbiome may be important predictors of symptomatic response after sinus surgery. Full article