Abstract Background The prevalence of asthma is rising globally, posing a significant public health burden. While obesity is a well-established risk factor for asthma, traditional metrics like Body Mass Index (BMI) have limitations in distinguishing visceral adiposity. The Body Roundness Index (BRI) is a novel geometric indicator of central obesity, but its longitudinal association with asthma risk in middle-aged and elderly populations remains unclear. Methods We conducted a retrospective cohort study using data from the China Health and Retirement Longitudinal Study (CHARLS) covering the period from 2011 to 2020. A total of 7,754 participants aged 45 years and older, free of respiratory diseases at baseline, were included. Multivariable Cox proportional hazards models and restricted cubic spline (RCS) analyses were employed to evaluate the association between BRI and the incidence of asthma. Results During a 7-year follow-up, 521 incident asthma cases were identified. In fully adjusted models, elevated BRI was significantly associated with an increased risk of asthma (Hazard Ratio [HR] = 1.39, 95% CI: 1.388–1.393 per SD increase). RCS analysis revealed a non-linear U-shaped relationship with a distinct inflection point at a BRI of 4.12. Beyond this threshold, the risk of asthma increased substantially (HR = 1.75, 95% CI: 1.34–2.27). Subgroup analyses demonstrated that the association was more pronounced in females and urban residents. Conclusion BRI is significantly associated with the risk of asthma in middle-aged and elderly Chinese adults, exhibiting a non-linear dose-response relationship. As a superior marker of visceral adiposity, BRI may serve as a simple and effective tool for identifying high-risk individuals, particularly women, to facilitate early screening and prevention strategies for asthma.

In clinical practice, a significant subgroup of patients with moderate-to-severe asthma reports persistent symptoms and substantial impairment in daily functioning despite high adherence to prescribed inhaled therapy. However, their lived experiences and unmet needs remain poorly understood. This descriptive phenomenological study aimed to explore the illness experiences, related barriers, and unmet needs of adults with moderate-to-severe asthma who remained persistently uncontrolled despite objectively verified high adherence to prescribed inhaled maintenance therapy. In-depth, semi-structured interviews were conducted with 14 adult patients between June and November 2025 in a specialty asthma clinic at a tertiary-level hospital in China, and the data were analyzed using Colaizzi's seven-step phenomenological method. Four overarching themes were identified, revealing a multidimensional hidden burden: (1) physiological instability, characterized by persistent symptoms and comorbidity-driven symptom amplification; (2) life-space constriction, involving occupational vulnerability, stigma, and defensive withdrawal; (3) psychological duality, in which fear and vigilance coexisted with resigned habituation; and (4) therapeutic dilemmas, including corticosteroid anxiety and dependence, financial toxicity, and fears of therapeutic futility. These findings show that persistent poor control in highly adherent patients is experienced not simply as ongoing symptoms, but as a multidimensional burden. This adherence paradox challenges the assumption that high adherence invariably indicates satisfactory control. The findings also highlight the need for nurse-led follow-up and future intervention studies focusing on symptom interpretation, uncertainty management, and treatment-related concerns in this subgroup.

Mitochondrial dysfunction drives persistent inflammation in severe asthma, yet its upstream metabolic regulation remains unclear. Induced sputum from patients with severe asthma was analyzed and integrated with transcriptomic datasets from independent cohorts. Two mouse models (C57BL/6J) were used for in vivo validation with multi-omics profiling, and mechanistic studies were performed in air-liquid interface-cultured primary human airway epithelial cells. Glutathione reduced form (GSHr) was markedly depleted in sputum and associated with poor disease control and mixed granulocytic inflammation in patients with severe asthma. Multi-omics analyses revealed coordinated disruption of glutathione (GSH) metabolism, including oxidized GSH accumulation, reduced synthesis and glutathione-S-transferase activity, and impaired mitochondrial GSH transport. GSH supplementation alleviated airway inflammation, oxidative stress, and mitochondrial dysfunction, whereas pharmacological inhibition of GST exacerbated these effects. Mitochondrial analyses identified suppressed SLC25A39 expression as a key mediator of defective GSH transport and redox imbalance. Transcriptomic profiling of airway biopsies showed upregulation of Neuropilin-1 (Nrp1), closely associated with altered glutathione pathways. Targeting the Nrp1 b1 domain restored mitochondrial GSH metabolism and attenuated airway inflammation. These findings identify an Nrp-centered metabolic pathway that disrupts mitochondrial homeostasis and drives inflammatory amplification, highlighting mitochondria-targeted therapeutic strategies for severe asthma.

BACKGROUND:The pathogenesis of early-stage skin lesions in diabetic foot (DF) remains poorly understood, and cannot be fully explained by conventional theories. Skin microbiota dysbiosis has recently emerged as a critical factor, but the underlying mechanisms remain unclear. METHODS:In this study, we integrated metabolomics and metagenomics analyses of skin samples to investigate metabolic dysregulation driven by microbial dysbiosis. RESULTS:We identified elevated serine as a key metabolic alteration strongly correlated with a dysbiotic microbiota structure. Functionally, we demonstrate that abnormal serine accumulation contributes to the dysregulation of the early skin immune microenvironment in the diabetic foot. Mechanistically, our results reveal that excess serine synergizes with lipopolysaccharide (LPS) to stimulate the release of eHsp90α from keratinocytes, which was strictly dependent on the Akt/mTOR/HIF-1α pathway. This released eHsp90α then acts as a damage-associated molecular pattern, promoting both the migration and subsequent pyroptotic cell death of macrophages. CONCLUSIONS:Collectively, our findings suggest a novel pathogenic axis where a microbiota-host derived metabolite collaborates with a bacterial endotoxin to promote inflammatory cell death, which is closely associated with early skin lesions in DF. This work not only elucidates a new mechanism for DF pathogenesis but also suggests that the serine-eHsp90α-pyroptosis axis may serve as a potential candidate for future therapeutic exploration.

BACKGROUND:Asthma is a chronic inflammatory airway disease characterized by epithelial barrier dysfunction, mucus hypersecretion, and type 2-skewed immune responses. Macrophages play a critical role in shaping airway inflammation and tissue remodeling, yet the molecular mechanisms regulating macrophage activation in allergic asthma remain incompletely understood. The vitamin D receptor (VDR) is an immune-modulatory transcription factor expressed in macrophages, but its macrophage-specific function and regulatory mechanisms in allergic airway inflammation remain unclear. METHODS:We investigated the role of macrophage VDR signaling using a chronic house dust mite (HDM)-induced asthma model combined with myeloid-specific Vdr conditional knockout mice. Airway inflammation, epithelial remodeling, and macrophage polarization were assessed by histological, molecular, and flow cytometric analyses. Mechanistic studies were performed to identify nuclear localization sequences (NLSs) of VDR and to evaluate their interaction with the nuclear import adaptor KPNA1. RESULTS:HDM exposure increased VDR expression in macrophages both in vivo and in vitro. Myeloid-specific deletion of Vdr significantly attenuated airway inflammation, reduced inflammatory cell recruitment, and alleviated epithelial barrier disruption and mucus metaplasia. Mechanistically, VDR promoted macrophage M2-like polarization in response to HDM stimulation. We further identified a previously unrecognized C-terminal nuclear localization sequence spanning amino acids 387-412 that is required for VDR nuclear translocation and macrophage polarization. Structural modeling and biochemical analyses indicated that phosphorylation within this region enhances the interaction between VDR and the nuclear import adaptor KPNA1, thereby facilitating nuclear import of VDR. CONCLUSIONS:These findings identify macrophage-intrinsic VDR signaling as an important regulator of allergic airway inflammation and reveal a phosphorylation-dependent mechanism controlling VDR nuclear trafficking and macrophage polarization.

Microplastics, as a novel type of environmental pollutant, have garnered increasing concern for their potential threat to human health. Pulmonary fibrosis, with high mortality and limited therapy, is exacerbated by airborne contaminants like microplastics. This research assessed the pathological role of polystyrene microplastic (PS-MPs) exposure in driving airway microbial dysbiosis and subsequent fibrotic lung remodeling. Mice were intranasally instilled with PS-MPs and treated with a mixture of antibiotics. Bronchoalveolar lavage fluid was collected from the mice, and the airway microbiota, along with their associated metabolic profiles, were characterized using 16S rRNA gene sequencing, non-targeted metabolomics, and network pharmacology. Exposure to PS-MPs significantly increased the abundance of Staphylococcus, Prevotella, and Weissella in the mouse airway and altered the structure of the lung microbiota. Microbiota derived metabolites, such as 5-methoxyindole-3-carboxaldehyde (5-MC), arachidonylamide, progesterone, and oleamide, were significantly negatively correlated with Staphylococcus, Prevotella, and Weissella, with 5-MC showing the largest fold change. Experimental data demonstrated that microbiota derived 5-MC attenuated particulate induced alveolar epithelial senescence via PI3K/AKT/mTOR pathway modulation, consequently reducing fibrotic pathology. This evidence establishes that PS-MPs initiate pulmonary fibrosis through dysbiosis-mediated metabolic disruption, whereas the microbial metabolite 5-MC counteracts PS-MPs triggered fibrosis by rescuing cellular aging processes.

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disorder with limited therapeutic options, necessitating the identification of novel pathogenic mechanisms and therapeutic targets. Here, we report a critical role for the RNA acetyltransferase NAT10 in driving pulmonary fibrosis through epitranscriptomic regulation of mitochondrial metabolism. We found that NAT10 and its catalyzed N4-acetylcytidine (ac4C) modification were significantly upregulated in fibrotic lungs from IPF patients and bleomycin-challenged mice, particularly within activated fibroblasts. Genetic ablation of NAT10 in fibroblasts markedly attenuated fibrotic progression, whereas its overexpression exacerbated the pathology. Mechanistically, integrated transcriptomic and biochemical analyses identified pyruvate dehydrogenase kinase 4 (PDK4) as a key downstream target whose mRNA stability was enhanced by NAT10-mediated ac4C modification. This post-transcriptional regulation led to PDK4 upregulation, which in turn promoted mitochondrial fission and reactive oxygen species production, thereby facilitating fibroblast-to-myofibroblast transition and excessive extracellular matrix deposition. Furthermore, we delineated the upstream regulation of NAT10, demonstrating that TGF-β1 transcriptionally induces NAT10 expression via direct Smad3 binding to its promoter, forming a positive feedback loop that sustains fibrotic activation. Our study unveils the NAT10-ac4C-PDK4 axis as a central regulator of mitochondrial dynamics in pulmonary fibrosis and highlights NAT10 as a promising therapeutic target for restoring metabolic homeostasis and ameliorating fibrotic lung remodeling.

Metabolic reprogramming of airway epithelial cells is a hallmark of asthma, yet the mechanisms by which altered metabolism drives inflammation remain largely unknown. Histone lactylation, a recently identified metabolism-derived epigenetic modification, may provide a mechanistic link. Clinical specimens and single-cell RNA sequencing (scRNA-seq) were analyzed to map the metabolic landscape of asthma. Histone lactylation in airway epithelial cells was assessed by western blotting and immunofluorescence. Functional roles of histone lactylation were evaluated via modulation of glycolysis, lactate availability, or P300 expression. Chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq) were performed to identify transcriptional targets of H3K18 lactylation (H3K18la). Glycolysis and histone lactylation, particularly H3K18la, were significantly elevated in the airway epithelial cells of asthma. Inhibition of glycolysis or P300 knockdown attenuated the inflammatory response by suppressing histone lactylation; whereas lactate supplementation exacerbated inflammation by promoting histone lactylation. H3K18la accumulated at the CSF1R promoter, directly enhancing its transcription and establishing a CSF1/CSF1R/MAPK autocrine positive feedback axis that positions airway epithelial cells as an upstream driver and inflammatory amplifier in allergic airway inflammation. This study defines a glycolysis–histone lactylation–CSF1R signaling axis that links epithelial metabolic reprogramming to sustained inflammatory gene activation in asthma, highlighting histone lactylation as a potential therapeutic target for allergic airway inflammation.

While neutrophils represent a prominent myeloid component in non-small cell lung cancer (NSCLC), the specific immunosuppressive functions of N2-polarized neutrophils and their mechanistic interactions with CD8⁺ T cells remain incompletely characterized. Furthermore, the development of clinically applicable models for prognostic stratification and immunotherapy response prediction, grounded in these molecular interactions, represents a critical unmet need. We integrated large-scale single-cell RNA sequencing datasets to delineate the tumor immune microenvironment, performing pathway enrichment and cell-cell communication analyses. Key molecular features derived from these interactions were employed to construct a deep neural network model. This model was trained and validated on bulk RNA sequencing cohorts to predict immunotherapy response. Additionally, we developed the N2_Neu-CD8⁺ Tex Loop Score (NTLS) for prognostic assessment and evaluated its pan-cancer applicability. Our analysis revealed a previously uncharacterized positive feedback loop between N2 neutrophils and exhausted CD8⁺ T cells (Tex). Neutrophil-derived ICAM1 engages with ITGAL/ITGB2 on CD8⁺ T cells, suppressing their NF-κB signaling and reinforcing the exhausted phenotype. In a feed-forward manner, Tex-derived CCL5 signals via CCR1 on N2 neutrophils, activating their NF-κB pathway and further upregulating ICAM1 expression. This ICAM1–Integrin and CCL5-CCR1 axis creates a self-sustaining immunosuppressive circuit. A deep learning model, built upon genes central to this loop, accurately predicted immunotherapy outcomes in NSCLC and melanoma. The derived NTLS score proved effective for prognostic stratification and was validated across multiple independent cohorts and cancer types. This study defines a pathogenic positive feedback loop, driven by ICAM1–Integrin and CCL5–CCR1 interactions, through which N2 neutrophils and Tex cells cooperatively establish an immunosuppressive niche that drives immunotherapy resistance. The computational models we developed, based on this molecular circuitry, offer robust tools for patient stratification and hold significant translational promise.

Objectives: Insomnia often leads to systemic chronic inflammation and is particularly common among asthma patients. However, the specific impact of insomnia on lung function and mortality in asthma patients remains unclear. This study aims to investigate the relationship between insomnia, lung function, and mortality in asthma patients, and further elucidate the potential role of inflammatory biomarkers in this association. Study design: This was a prospective cohort study. Methods: This prospective cohort study using data from the UK Biobank included 37250 participants with asthma. Multiple linear regression and Cox proportional hazards models were separately used to explore the relationships between insomnia, lung function, and mortality. Mediation analysis assessed the mediating effects of inflammatory biomarkers. Results: Compared to those without insomnia, frequent insomnia was associated with a 0.06 decline in FEV1 (Z-score) and a 0.11 reduction in FEV1/FVC (Z-score). The Hazard ratios (HRs) for individuals with frequent insomnia were 1.10 (95 % CI: 1.01-1.19) for all-cause mortality and 1.15 (95 % CI: 1.02-1.29) for cancer-related mortality. Inflammatory biomarkers mediated the association between insomnia and mortality, proportions(%) were WBC (5.86), NEU (11.9), SII (5.71), LCR (15.3) and CRP (13.8). Conclusion: Insomnia in asthma patients is negatively associated with lung function and increases the risks of both all-cause and cancer-related mortality. Inflammatory biomarkers partially mediate this association.

Asthma is a chronic respiratory disease with increasing global prevalence, often linked to disrupted airway microbiota. Azithromycin has shown promise in asthma treatment, but whether its effect is owing to its antimicrobial capacity remains largely unknown. A house dust mite (HDM)-induced asthmatic mouse model was used to evaluate the effects of azithromycin on airway inflammation and microbiota. Mice were divided into control, HDM-induced asthma, HDM + azithromycin, and azithromycin-alone groups. Airway microbiota was analyzed using 16S rRNA sequencing, and metabolomic profiles were assessed via liquid chromatography-tandem mass spectrometry. Azithromycin alleviated type 2 airway inflammation in HDM-induced asthma, restoring microbiota diversity by modulating specific genera, including Streptococcus, Staphylococcus, Ruminococcus, Coprococcus, Bifidobacterium, etc. Combination analysis with metabolomics revealed that azithromycin significantly regulated airway microbiota-associated sphingomyelin metabolism. Azithromycin's therapeutic effects in asthma are associated with its ability to regulate airway microbiota and its associated sphingomyelin metabolism, highlighting the potential for microbiota-targeted therapies in asthma.IMPORTANCEAsthma, a prevalent chronic respiratory condition, poses a significant global health challenge due to its increasing prevalence and associated morbidity. The role of airway microbiota in asthma pathogenesis is gaining attention, with evidence suggesting that disruptions in this microbial community contribute to disease severity. Our study investigates the impact of azithromycin, a macrolide antibiotic, on airway inflammation and microbiota in a mouse model of asthma. The findings reveal that azithromycin not only alleviates airway inflammation but also restores microbiota diversity and modulates microbiota-associated sphingomyelin metabolism. This research underscores the potential of microbiota-targeted therapies in asthma management, offering a novel therapeutic strategy that could improve patient outcomes and reduce the healthcare burden associated with asthma.

Asthma is a common respiratory disease characterized by chronic inflammation and airway obstruction, with airway epithelial damage playing a pivotal role in pathogenesis. Existing treatments regulate inflammation without addressing epithelial barrier repair, indicating the need for therapeutic agents that target damaged epithelial cells. This study evaluates the effects of bacterial cellulose (BC), a biocompatible polymer with anti-inflammatory and pro-regenerative properties, as a promising therapeutic candidate for asthma. In a mouse model of house dust mite (HDM)-induced allergic asthma, intranasal BC administration markedly reduces both airway inflammation and mucus hypersecretion while also improving epithelial barrier integrity. Bronchoalveolar lavage fluid (BALF) metabolomics and single-cell RNA sequencing of human asthmatic epithelium samples reveal that BC downregulates epithelial CDP-diacyl glycerol synthase 1 (CDS1), resulting in decreased synthesis of phosphatidylinositol (PI) and PI 4,5- bisphosphate (PI(4,5)P₂) and suppression of phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling. CDS1 overexpression reverses the effect of BC on asthma in vivo, confirming that CDS1 is a key target. BC administration alleviates asthma by repairing the epithelial barrier and inhibiting PI3K/AKT signaling via CDS1-dependent PI reprogramming. Thus, treatment with BC represents a promising therapeutic strategy for asthma, with dual actions in repairing epithelial barrier dysfunction and mitigating inflammation.

Growing evidences have suggested the airway microbiota may participate in lung cancer progression. However, little was known about the relationship between airway microbiota and lung cancer associated systemic inflammation. Here we aimed to explore the association between sputum microbiota and systemic inflammation in lung cancer. The microbiota of spontaneous sputum samples from 51 non-small cell lung cancer (NSCLC) patients and 6 patients with lung benign nodules were sequenced via 16 S rRNA sequencing. Neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and C reactive protein (CRP) were used to represent systemic inflammation. Patients were divided into 2 groups based on level of inflammatory biomarkers respectively (CRP_low versus CRP_high; NLR_low versus NLR_high; PLR_low versus PLR_high). alpha-diversity was significantly decreased in CRP_high and NLR_high patients. beta diversity analysis based on weighted unifrac distance indicated that microbial community structure differed significantly between patients with different inflammation status. Lefse identified genera Porphyromonas, Selenomonas, Moryella, Megasphaera, Corynebacterium were enriched in CRP_low group. Compared with NLR_high, genera Veillonella, Neisseria, Bulleidia, Moryella were enriched in NLR_low group. For patients with different PLR level, genera Veillonella, Prevotella, Moryella, Selenomonas were increased in PLR_ low patients. Function analysis identified propionate metabolism pathway was significantly enriched in CRP_low and PLR_low groups. Moreover, RDA analysis showed that compared with PLR, NLR and CRP had strongest association with microbial community. Airway microbial structure differed between lung cancer with different systemic inflammation status. Patients with relative high inflammation status were associated with alteration of specific airway genera and microbial metabolic function.

Inhaled environmental allergens, such as house dust mites (HDM), have been shown to induce an inflammatory reaction, tissue injury, and increased airway sensitivity in the lungs, ultimately leading to the development of allergic asthma. The imbalance of respiratory microbiota and metabolites plays a crucial role in the progression of allergic asthma. However, there is limited knowledge available regarding the alterations in respiratory microbiota and metabolites and their impact on the host in the context of asthma. The aim of this study was to investigate the potential pathways involved in the development of asthma through the analysis of lung flora and metabolites. A mouse model of house dust mite (HDM)-induced asthma was established, and alveolar lavage samples were collected for microbiome 16S rRNA sequencing and untargeted metabolic analysis. Microbiological analyses indicated a significant alteration in the microbiota after 4 and 6 weeks of HDM nebulisation stimulation. This was characterized by a decrease in microbial diversity, as well as reductions in the relative proportion of Gallionella and Lactobacillus. Conversely, the abundance of Flavobacterium and Ralstonia increased in the HDM4W and HDM6W groups, respectively. Metabolomic analyses revealed seven distinct metabolites, among them L-malic acid, which were linked to signaling pathways in a mouse model of HDM-induced asthma. The correlation analysis demonstrated a positive association between L-malic acid and Rhodanobacter and Nocardioides. L-malic acid was discovered to be efficacious in reducing airway inflammation in mice with house dust mite-induced asthma. Further analysis revealed that this change was linked to lipid peroxidation and changes in ferroptosis markers, namely GPX4 and FTH. These findings suggest that L-malate inhibits ferroptosis. However, the introduction of ferroptosis inducers, such as Erastin, was observed to negate the beneficial effect of butyrate. In summary, this research implies that the respiratory microbiota metabolite L-malic acid lessens airway inflammation in asthma by inhibiting ferroptosis, offering a potential approach for managing asthma.

Immune-related adverse reactions (irAEs) are common adverse reactions after immune checkpoint inhibitor treatment, impacting the universality and continued use of immunotherapy. Currently, preclinical models to investigate the mechanisms underlying these adverse effects are inadequate. This study aims to develop both in vitro and in vivo models of irAEs to advance basic research on these adverse reactions. For vitro models, we designed two co-culture systems: "Lung epithelial cells-PBMC" conditional co-culture model and "organoid-PBMCs" co-culture model. These involve culturing spheroids, patient-derived organoids and isolating, expanding, and co-culturing peripheral blood mononuclear cells (PBMCs). For vivo model, PD1 humanized mice were used to establish a lung carcinoma in situ model in offspring, with blocked immune checkpoints to induce systemic inflammatory responses. Mice without PD-1 blockade served as the control group. In both organoid and "lung epithelial cell-PBMC" models, compared with the control group, the PBMC+anti-PD1 group exhibited inflammatory injury, demonstrated by the worst activity, increased collagen deposition, elevated mRNA levels of αSMA and Vimentin, higher Fibronectin expression, and higher inflammatory factors (IL6, IL1β, MPO) in the culture supernatant (p < 0.05). In vivo model also showed pulmonary inflammation, with slower weight gain of the affected mice, more obvious pulmonary interstitial thickening(Masson staining and α-SMA immunofluorescence staining), and increased immune cells and IL17A in alveolar lavage fluid and serum. This study successfully developed preclinical models of irAEs using organoid technology, conditioned co-culture and humanized mouse models, effectively reproducing inflammatory injury and offering valuable tools for irAE research.

Acute lung injury (ALI) is a severe inflammatory condition marked by alveolar damage and cytokine dysregulation. Exosomes, as carriers of bioactive molecules, regulate immune responses through intercellular communication. However, the cytokine profile of serum-derived exosomes during ALI remains unclear, and their functional role in modulating inflammation is poorly defined. A murine model of ALI was established via intraperitoneal injection of lipopolysaccharide (LPS, 10 mg/kg), and samples were collected at 2 h and 8 h post-injection. Lung injury severity was assessed using hematoxylin and eosin staining and lung W/D weight ratio. Serum-derived exosomes were isolated using the ExoQuick precipitation method and characterized by transmission electron microscopy and western blotting. Cytokine and chemokine profiles were quantified using a 32-plex Luminex xMAP assay. Exosome-mediated immune modulation was evaluated through a scratch migration assay in RAW264.7 macrophages. LPS treatment led to increased pulmonary edema and histopathological damage, which were more pronounced at 8 h. A total of 14 cytokines in the serum, including IL-6, TNF-α, and MCP-1, were significantly elevated at either 2–8 h compared to the control group. However, chemokines such as IP-10, G-CSF, and MIP-1β were markedly upregulated in serum-derived exosomes from ALI mice. Functional assays demonstrated that exosomes from ALI mice significantly enhanced the migratory capacity of RAW264.7 macrophages. This study demonstrates that serum-derived exosomes from ALI mice are enriched in specific chemokines and promote macrophage migration in vitro. These findings suggest that exosomes may participate in inflammatory cell recruitment during ALI and hold potential as biomarkers or modulators in the inflammatory response.

ABSTRACT Lung cancer is a leading cause of cancer mortality, with non-small cell lung cancer (NSCLC) comprising the majority of cases. Despite the advent of immune checkpoint inhibitors (ICIs), a significant number of patients fail to achieve a durable response, highlighting the need to understand the factors influencing treatment efficacy. Saliva samples and tumor samples were collected from 20 NSCLC patients. The salivary microbiota was profiled using metagenomic next-generation sequencing, and metabolites were analyzed via liquid chromatography-mass spectrometry to identify correlations among bacteria, metabolites, and immunotherapy responses. Immunohistochemistry (IHC) analysis of tissue samples verified the result. Besides, in vitro experiments and tumor tissue microarray, including 70 NSCLC patients, were utilized to further explore the potential mechanism linking the oral microbiome and immunotherapy efficacy. The study revealed several differential species and distinct metabolite compositions between responders and non-responders to ICI therapy in NSCLC and explored correlations and mechanisms between microbiota metabolites and immunotherapy resistance. Notably, it was found that several Neisseria and Actinomyces species were significantly enriched in responders and identified lipids and lipid-like molecules associated with PD-L1 expression levels and treatment outcomes. Importantly, several differential lipid molecules were associated with differential species. Further, in vitro experiments and IHC experiments indicated that abnormal fat metabolism linked to dysbiosis is correlated with immunotherapy resistance through regulation of CD8+ T cell activity/infiltration and PD-L1 expression. Specific saliva microbiome and its associated lipids metabolites are significantly associated with the efficacy of ICI-based therapy in lung cancer. Our findings suggest that oral microbiome modulation and targeting lipid metabolism could improve immunotherapy responses, offering new avenues for personalized treatment strategies.IMPORTANCEIn non-small cell lung cancer, our study links specific salivary microbiome profiles and related lipid metabolites to the efficacy of immune checkpoint inhibitor (ICI) therapies. Responders showed enrichment of certain Neisseria and Actinomyces species and distinct lipid compositions. These lipids correlate with PD-L1 expression and CD8+ T cell activity, affecting treatment outcomes. Our results imply that modulating the oral microbiome and targeting lipid metabolism may enhance ICI effectiveness, suggesting novel personalized therapeutic approaches.

Lung cancer is the leading cause of cancer-related death worldwide, and patients with distant metastasis have a poor prognosis. Various studies have reported that microbiota and metabolites significantly differ between healthy individuals and lung cancer patients. However, the effects of metabolites on tumor formation and metastasis are unclear. Therefore, our study aimed to determine the correlation between airway metabolites and microbiota, along with their respective roles in lung cancer metastasis. Bronchoalveolar lavage fluid (BALF) samples were collected from 30 non-small cell lung cancer (NSCLC) patients, including 11 patients without metastasis (M0) and 19 patients with metastasis (M1). Integrated pathogenic metagenomic and Liquid chromatography-mass spectrometry (LC‒MS) analyses were employed to explore differences between two groups. The omics data were analyzed and integrated via Spearman’s correlation coefficient. Specific metabolites were subsequently used to intervene in lung cancer cells and animal models to assess their influence on tumor metastasis. A total of 801 metabolites were identified in the BALF of all patients. Compared with those in the M0 group, 48 metabolites in the M1 group were significantly different. D-phenylalanine was notably upregulated in M1 and was positively related to Metamycoplasma salivarium. Intranasal administration of D-phenylalanine promoted tumor intrapulmonary metastasis and induced epithelial mesenchymal transition (EMT) process in NSCLC mouse models. Moreover, D-phenylalanine promotes the proliferation of non-small cell lung cancer cells and facilitates their migration and invasion via EMT. The airway microbiota associated D-phenylalanine could promote lung cancer metastasis via EMT, which could be a new predictor for the diagnosis of tumor metastasis in NSCLC patients.