Emerging pathogenic links between microbiota and the gut-lung axis

Unraveling cysteinyl leukotrienes and their receptors in inflammation through the brain-gut-lung axis

Cysteinyl leukotrienes (CysLTs), as potent lipid inflammatory mediators, play a pivotal role in systemic multi-organ inflammation and inter-organ communication through interactions with their receptors (CysLTRs). However, However, the function of CysLT3R is unclear and lacks a network of cross-organ metabolite interactions, and the clinical use of leukotriene receptor antagonists (LTRAs) has certain limitations. This review systematically synthesizes existing evidence and proposes future directions by clarifying receptor subtype specificity, optimizing targeted therapies, exploring CysLTs' applications in neuroimmunology, and elucidating the dual roles of CysLTs in chronic inflammation. It is indicated that CysLTs activate eosinophils, mast cells, and airway tuft cells, driving type 2 immune responses and mucus secretion in the lungs, thereby exacerbating respiratory diseases such as asthma. In the nervous system, CysLTs aggravate neurodegenerative disorders like cerebral ischemia and Alzheimer's disease by disrupting the blood-brain barrier, promoting glial activation, and inducing neuronal damage. In the gut, CysLTs regulate anti-helminth immunity via the tuft cell-ILC2 pathway and collaborate with prostaglandin D2 (PGD2) to modulate bile excretion and mucosal protection. Furthermore, CysLTs mediate communication through the gut-lung and gut-brain axes via metabolites such as succinate, contributing to cross-organ inflammatory regulation. In conclusion, this review highlights the complex roles of CysLTs in chronic inflammation, providing a theoretical foundation for precise intervention in multi-organ inflammatory diseases, which provides a theoretical framework for precision interventions in multi-organ inflammatory diseases and inspires interdisciplinary breakthroughs.

Maternal probiotic exposure enhances CD8 T cell protective neonatal immunity and modulates offspring metabolome to control influenza virus infection

Maternal gut microbiota composition contributes to the status of the neonatal immune system and could influence the early life higher susceptibility to viral respiratory infections. Using a novel protocol of murine maternal probiotic supplementation, we report that perinatal exposure to Lacticaseibacillus rhamnosus (L.rh) or Bifidobacterium animalis subsp. lactis (B.lac) increases the influenza A/PR8 virus (IAV) clearance in neonates. Following either supplementation, type 1 conventional dendritic cells (cDC1) were amplified in the lymph nodes leading to an enhanced IAV antigen-experienced IFN-γ producing effector CD8 T cells in neonates and IAV-specific resident memory CD8 T cells in adulthood. This was compatible with a higher protection of the offspring upon a secondary infection. Interestingly, only mice born to L.rh supplemented mothers further displayed an increased activation of IFN-γ producing virtual memory CD8 T cells and a production of IL-10 by CD4 and CD8 T cells that could explain a better control of the lung damages upon infection. In the offspring and the mothers, no disturbance of the gut microbiota was observed but, as analyzed through an untargeted metabolomic approach, both exposures modified neonatal plasma metabolites. Among them, we further demonstrated that genistein and 3-(3-hydroxyphenyl)propionic acid recapitulate viral clearance or cDC1 activation in neonates exposed to IAV. We conclude that maternal L.rh or B.lac supplementation confers the neonates specific metabolomic modulations with a better CD8 T cell-mediated immune protection against IAV infection.

Probiotic effects of Clostridium cellabutyricum against Pseudomonas aeruginosa infection in an antibiotic-induced gut microbial dysbiosis mouse model

OBJECTIVE

Gut microbiota dysbiosis induced by antibiotic use weakens its colonization resistance against opportunistic pathogens, increasing the risk of invasion and infection. While probiotics have the potential to restore the impaired gut microbial structure and prevent respiratory tract infections, the effectiveness of specific strains and the underlying mechanisms remain largely unexplored. In this study, the preventive effects of a novel butyrate-producing bacterium, Clostridium cellabutyricum YQ-FP-027T against Pseudomonas aeruginosa infection after antibiotic exposure were investigated in antibiotic-pretreated mice model.

METHODS

Phenotypic characterizations including the bacterial load in the lung, the assessment of gene expression of immune factors in lung tissue using qPCR, and detection of gut microbial composition using 16S rRNA sequencing were conducted. Pulmonary bacterial load and expression levels of immune factors of lung tissue, and gut microbial composition were evaluated.

RESULTS

Our results demonstrated that YQ-FP-027T ameliorated lung tissue integrity, significantly reduced pulmonary bacterial burden, and decreased the expression of interleukin-1β and TNF-α, while enhancing the expression of interleukin-10 and cathelicidin-related antimicrobial peptide. Furthermore, YQ-FP-027T increased the abundance of Lachnospiraceae in the gut and reduced the abundance of opportunistic pathogens such as Enterococcaceae and Helicobacteraceae.

CONCLUSIONS

These results suggest YQ-FP-027T exerts probiotic effects by restoring gut microbiota balance, enhancing intestinal barrier function, and positively influencing pulmonary immune responses through the gut-lung axis. This study reveals the preventive potential of YQ-FP-027T against P. aeruginosa infection in the context of gut microbiota dysbiosis, offering a novel preventive strategy.

Metabarcoding analysis of the microbiota in flocks naturally infected by Coxiella burnetii: First description of the global microbiota in domestic small ruminants

This study investigates Q fever in sheep and goats, key reservoirs for human infection, by metabarcoding and comparing it with q-PCR and serology. Samples from 26 small ruminants (aborted and normal-delivery) and six males across three Q fever-affected herds were analyzed. In sheep herds, seropositivity was 50 and 80 % respectively, with Coxiella (C.) burnetii shedding detected vaginally in the second herd. In goats, 100 % seropositivity and 90 % C. burnetii detection were observed, with nasal and vaginal samples showing the highest detection rates. Metabarcoding revealed significant differences in alpha diversity, with greater richness in blood and evenness in milk from normal-delivery sheep and higher evenness in faeces from aborted sheep. Beta diversity showed distinct vaginal microbiota in normal-delivery females compared to aborted ones. Firmicutes was the most abundant phylum observed. Dominant genera included: Moraxella (nasal), Mycoplasma (blood), Streptococcus (milk), Ureaplasma (vaginal and preputial), Rikenellaceae RC9 gut group (faeces). Significant differences in bacterial composition, including infertility-linked vaginal pathogens, were found across female groups in all herds in the anatomical locations studied, revealing new species and tropisms. Moreover, taxonomic analysis identified C. burnetii in vaginal, milk and environmental samples. This first report of C. burnetii in the caprine nasal cavity suggests an underestimated tropism that may improve Q fever diagnosis. These findings underscore the need for herd-wide Q fever control measures, including males and normal-delivery females. Our findings contribute to new insights into the pathogen's impact on small ruminant microbiota and a novel approach to studying infectious diseases in this sector.

Intestinal microbiota and respiratory system diseases: Relationships with three common respiratory virus infections

In recent years, the role of the intestinal microbiota in regulating host health and immune balance has attracted widespread attention. This study provides an in-depth analysis of the close relationship between the intestinal microbiota and respiratory system diseases, with a focus on three common respiratory virus infections, including respiratory syncytial virus (RSV), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and influenza virus. The research indicates that during RSV infection, there is a significant decrease in intestinal microbial diversity, suggesting the impact of the virus on the intestinal ecosystem. In SARS-CoV-2 infection, there are evident alterations in the intestinal microbiota, which are positively correlated with the severity of the disease. Similarly, influenza virus infection is associated with dysbiosis of the intestinal microbiota, and studies have shown that the application of specific probiotics exhibits beneficial effects against influenza virus infection. Further research indicates that the intestinal microbiota exerts a wide and profound impact on the occurrence and development of respiratory system diseases through various mechanisms, including modulation of the immune system and production of short-chain fatty acids (SCFAs). This article comprehensively analyzes these research advances, providing new perspectives and potential strategies for the prevention and treatment of future respiratory system diseases. This study not only deepens our understanding of the relationship between the intestinal microbiota and respiratory system diseases but also offers valuable insights for further exploring the role of host-microbiota interactions in the development of diseases.

Nicotinamide modulates gut microbial metabolic potential and accelerates recovery in mild-to-moderate COVID-19

Cellular NAD+ depletion, altered tryptophan metabolism and gut microbiome dysbiosis are associated with disease progression and unfavourable clinical outcomes in COVID-19. Here, we show that supplementing tryptophan metabolism with nicotinamide alleviates COVID-19 symptoms. We evaluate a 4-week intervention with a novel nicotinamide formulation (1,000 mg) in a prospective, double-blind, randomized, placebo-controlled trial in 900 symptomatic outpatients with PCR-proven COVID-19. In the primary analysis population of participants at risk for severe COVID-19, 57.6% of those receiving nicotinamide and 42.6% receiving placebo recover from their performance drop at week 2 (P = 0.004). Nicotinamide is also beneficial for returning to normal activities (P = 0.009). Effects on gut metagenomic signatures parallel clinical efficacy, suggesting that nicotinamide influences COVID-19-associated faecal microbiome changes. After 6 months, responders to nicotinamide in acute COVID-19 show fewer post-COVID symptoms than placebo responders (P = 0.010). No relevant safety signals are observed. Overall, our results show that nicotinamide leads to faster recovery of physical performance and modulates COVID-19-associated faecal microbiome changes.

Protective effect of aqueous extract of Reineckea carnea (Andrews) Kunth against cigarette smoke-induced chronic obstructive pulmonary disease in mice and its impact on gut microbiota

Reineckea carnea (Andrews) Kunth (RCK) is known for its anti-inflammatory and antioxidant effects. But, its effects and underlying mechanisms on chronic obstructive pulmonary disease (COPD) are not well understood. This study aimed to evaluate the effects of RCK on COPD and to elucidate the mechanisms by which it modulates gut microbiota. A COPD mouse model was established through exposure to cigarette smoke (CS). Mice were then treated with oral administration of RCK aqueous extract. The anti-inflammatory effects and efficacy of RCK aqueous extract on COPD, as well as changes in microbiota composition, were evaluated. RCK aqueous extract ameliorated gut dysbiosis in CS-induced COPD mice by increasing the abundance of beneficial bacterial phyla and reducing the proliferation of pathogenic bacteria. Importantly, RCK treatment inhibited the expression of inflammatory mediators, such as IL-6, IL-8, and TNF-α at both mRNA levels and protein levels, attenuated oxidative stress in vivo in mice, and suppressed CS-induced activation of the NF-κB signaling pathway, thereby attenuating lung inflammation and restoring lung tissue structure. In conclusion, the beneficial effects of RCK aqueous extract on CS-induced COPD may be attributed to its anti-inflammatory and antioxidant properties as well as its ability to modulate gut microbial composition.

Auricularia auricula polysaccharides alleviate experimental silicosis by targeting EGFR through the "gut-lung axis"

Silicosis is a major public health problem and remains a challenge for clinicians. There is an urgent need to find new drugs to minimize disease progression and deterioration. Auricularia auricula-juade is a traditional folk medicine that is used for nourishing lung functions. The aim of this study is to investigate the pharmacological action and potential mechanism of polysaccharides in Auricularia auricula for silicosis treatment. The results indicated that the Auricularia auricula polysaccharide (AAP) effectively improved silicosis induced by silica (SiO2) in mice. The preliminary screening of differentially expressed proteins (DEPs) in the lung and intestinal tissues after AAP intervention was performed using tandem mass tag (TMT) quantitative proteomics. A common differential protein of the intestine and lungs, i.e., epidermal growth factor receptor (EGFR), was focused on using a combination of current proteomics data and a network disease database. After further validation, the use of an intestinal-lung co-culture model confirmed that AAP had the ability to attenuate the secretion of EGFR ligands (i.e., TGF-α, EGF and AREG) and modulate signaling between the intestine and lungs. This effectively inhibited the EGFR/JNK signaling pathway in lung tissues, thereby achieving therapeutic efficacy against silicosis. This study provides a solid experimental foundation of the use of AAP for silicosis treatment.

Integrating microbial GWAS and single-cell transcriptomics reveals associations between host cell populations and the gut microbiome

Microbial genome-wide association studies (GWAS) have uncovered numerous host genetic variants associated with gut microbiota. However, links between host genetics, the gut microbiome and specific cellular contexts remain unclear. Here we use a computational framework, scBPS (single-cell Bacteria Polygenic Score), to integrate existing microbial GWAS and single-cell RNA-sequencing profiles of 24 human organs, including the liver, pancreas, lung and intestine, to identify host tissues and cell types relevant to gut microbes. Analysing 207 microbial taxa and 254 host cell types, scBPS-inferred cellular enrichments confirmed known biology such as dominant communications between gut microbes and the digestive tissue module and liver epithelial cell compartment. scBPS also identified a robust association between Collinsella and the central-veinal hepatocyte subpopulation. We experimentally validated the causal effects of Collinsella on cholesterol metabolism in mice through single-nuclei RNA sequencing on liver tissue to identify relevant cell subpopulations. Mechanistically, oral gavage of Collinsella modulated cholesterol pathway gene expression in central-veinal hepatocytes. We further validated our approach using independent microbial GWAS data, alongside single-cell and bulk transcriptomic analyses, demonstrating its robustness and reproducibility. Together, scBPS enables a systematic mapping of the host-microbe crosstalk by linking cell populations to their interacting gut microbes.

Gut microbiota-lncRNA/circRNA crosstalk: implications for different diseases

The gut microbiota features an abundance of diverse microorganisms and represents an important component of human physiology and metabolic homeostasis, indicating their roles in a wide array of physiological and pathological processes in the host. Maintaining balance in the gut microbiota is critical for normal functionality as microbial dysbiosis can lead to the occurrence and development of diseases through various mechanisms. Long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) are non-coding RNAs that perform important regulatory functions for many processes. Furthermore, the gut microbiota and lncRNAs/circRNAs are known to interact in a range of both physiological and pathological activities. In this article, we review existing research relevant to the interaction between the gut microbiota and lncRNAs/circRNAs and investigate the role of their crosstalk in the pathogenesis of different diseases. Studies have shown that, the gut microbiota can target lncRNAs ENO1-IT1, BFAL1, and LINC00152 to regulate colorectal cancer development via various signaling pathways. In addition, the gut microbiota can influence mental diseases and lung tumor metastasis by modulating circRNAs such as circNF1-419, circ_0001239, circHIPK2 and mmu_circ_0000730. These findings provide a theoretical basis for disease prevention and treatment and suggest that gut microbiota-lncRNA/circRNA crosstalk has high clinical value.

Health benefits of medicinal plant natural products via microbiota-mediated different gut axes

This review examines the multifaceted roles of medicinal plant natural products in influencing gut microbiota and their subsequent impact on various organ systems through established gut axes, including the gut-brain, gut-liver, gut-heart, gut-lung, and gut-kidney axes. Medicinal plant natural products have exhibited diverse pharmacological activities, including modulation of microbiota composition, enhancement of metabolic processes, and alleviation of inflammation and oxidative stress. Evidence suggests that these components can ameliorate conditions such as neurological disorders, metabolic syndrome, and chronic kidney disease by restoring microbial balance and improving gut barrier integrity. Furthermore, the review highlights the potential of medicinal plant natural products to foster beneficial microbial communities and improve gut health, which may lead to reduced disease severity and inflammation. By comprehensively analyzing current literature, this review provides a foundation for future research aim at exploring the therapeutic applications of medicinal plant natural products in disease prevention and treatment. The findings underscore the need for further studies to elucidate the underlying mechanisms of action and validate the clinical efficacy of medicinal plant natural products in managing chronic conditions through gut microbiota modulation.

Investigation of Clostridium butyricum on atopic dermatitis based on gut microbiota and TLR4/MyD88/ NF-κB signaling pathway

BackgroundProbiotics, as common regulators of the gut microbiota, have been used in research to alleviate clinical symptoms of atopic dermatitis (AD).ObjectiveOur research team has previously identified a potential relieving effect of Clostridium butyricum on the treatment of AD, but the specific mechanism of how Clostridium butyricum alleviates AD has not yet been confirmed.MethodsIn this study, we explored the relieving effect of Clostridium butyricum on AD through in vivo and in vitro experiments. AD mice induced by 2,4-dinitrofluorobenzene (DNFB) were orally administered with 1 × 108 CFU of Clostridium butyricum for three consecutive weeks.ResultsOral administration of Clostridium butyricum reduced ear swelling, alleviated back skin lesions, decreased mast cell and inflammatory cell infiltration, and regulated the levels of inflammation-related cytokines. Clostridium butyricum activated the intestinal immune system through the TLR4/MyD88/NF-κB signaling pathway, suppressed the expression of inflammatory factors IL-10 and IL-13, and protected the damaged intestinal mucosa.ConclusionClostridium butyricum administration improved the diversity and abundance of the gut microbiota, enhanced the functionality of the immune system, and protected the epidermal barrier.

Cordyceps militaris alleviates COPD by regulating amino acid metabolism, gut microbiota and short chain fatty acids

ETHNOPHARMACOLOGICAL RELEVANCE

Chronic obstructive pulmonary disease (COPD) is a global health challenge with the high morbidity and mortality. Cordyceps militaris (CM) is a medicinal fungus that has been widely used in Asia for centuries. It has the effects of tonifying the lung and kidney, replenishing essence, resolving phlegm, and stopping bleeding. CM has been used clinically for alleviating COPD in China. However, the potential mechanism of CM in treating COPD remains indistinct.

PURPOSE

This article aimed to evaluate the efficacy and investigate the underlying mechanism of CM in treatment of COPD.

METHODS

The ingredients in CM were identified by LC Q/TOF-MS. The effect of CM in COPD was evaluated. Untargeted metabolomics assay and 16S rDNA sequencing were employed to examine the changes in metabolites and gut microbiota in COPD mice. Gut microbiota ablation experiment and quantification of short chain fatty acids (SCFAs) were integrated to elucidate the systematic mechanism of CM in treatment of COPD.

RESULTS

A total of 22 ingredients were identified in CM. CM alleviated COPD significantly by improving lung function and inhibiting pulmonary inflammation. Subsequently, 11 differential metabolites regulated by CM were mainly associated with amino acid metabolism. CM ameliorated the dysbiosis of intestinal microbiota in COPD mice, which contributed to the treatment of COPD. Moreover, CM increased the contents of SCFAs, including acetate, propionate, butyrate and isobutyrate. Spearman correlation indicated a close relationship among pulmonary function, differential metabolites, and gut microbiota.

CONCLUSIONS

This study revealed that CM alleviated COPD by regulating amino acid metabolism, ameliorating the imbalance of gut microbiota and increasing the SCFAs. These findings not only establish a foundation for the research of CM but also provide a basis for new treatment strategies of COPD.

Bidirectional Mendelian randomization and potential mechanistic insights into the causal relationship between gut microbiota and malignant mesothelioma

Malignant mesothelioma (MM) is a rare but aggressive cancer originating from mesothelial cells, which presents significant challenges to patients' physical and psychological well-being. The gut-lung axis underscores the connection between gut microbiota and respiratory diseases, with emerging evidence suggesting a strong association between gut microbiota and the development of MM. In this study, we conducted a two-sample Mendelian randomization (MR) analysis to investigate the potential causal relationship between gut microbiota and MM, while also exploring the underlying mechanisms through bioinformatics approaches. Gut microbiota summary data were obtained from the MiBioGen consortium, while MM data were sourced from the FinnGen R11 dataset. Causality was examined using the inverse variance weighted method as the primary analysis. Additional methods, including the weighted median, simple mode, MR-Egger, and weighted mode, were also employed. The robustness of the findings was validated through sensitivity analyses, and reverse causality was considered to further strengthen the MR results. Moreover, bioinformatics analyses were conducted on genetic loci associated with both gut microbiota and MM to explore potential underlying mechanisms. Our study suggests that genetically predicted increases in class.Bacilli, family.Rikenellaceae, genus.Clostridium innocuum group, and order.Lactobacillales were suggestively associated with a higher risk of MM, whereas increases in genus.Ruminococcaceae UCG004, genus.Flavonifractor, phylum.Firmicutes, genus.Anaerofilum, genus.Clostridium sensu stricto 1, and genus.Lactobacillus appeared to confer protective effects. Bioinformatics analysis indicated that differentially expressed genes near loci associated with gut microbiota might affect MM by modulating pathways and the tumor microenvironment. The results of this study point to a potential genetic predisposition linking gut microbiota to MM. Further experimental validation is crucial to confirm these candidate microbes, establish causality, and elucidate the underlying mechanisms.

Probiotics for children with asthma: a systematic review and meta-analysis

Background

Asthma is a common chronic inflammatory disease affecting children worldwide. While probiotics have been proposed as a potential therapy, their efficacy in pediatric asthma management remains controversial.

Methods

A systematic search of PubMed, Web of Science, Embase, Cochrane Central Register of Controlled Trials (CENTRAL) and clinicaltrials.gov was conducted to identify randomized controlled trials (RCTs) from 2014 to 2024 evaluating probiotic interventions in children with asthma. Primary outcomes included asthma exacerbation rates and predicted FEV1%. The risk of bias was assessed using Cochrane guidelines.

Results

Out of 1,361 articles, eight RCTs involving 902 participants were included. Meta-analysis showed probiotics significantly reduced acute asthma episodes with risk ratio of 0.38 (95% CI: 0.26-0.56, p < 0.00001) and improved FEV1/FVC ratios (MD = 5.70, 95% CI: 1.93-9.47, p < 0.003) compared to the control group. Neither FEV1 levels nor school attendance showed significant changes.

Conclusion

Probiotic supplementation may reduce asthma exacerbations and improve pulmonary function in pediatric asthma. However, heterogeneity across studies suggests the need for further research to determine optimal strains, dosages, and treatment durations. This review establishes groundwork for research and practice by exploring microbial interventions in childhood airway disorders.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/view/CRD42024607569, identifier (CRD42024607569).

Lactiplantibacillus plantarum -derived extracellular vesicles alleviate acute lung injury by inhibiting ferroptosis of macrophages

Despite considerable advancements in understanding the mechanisms of ALI, the therapeutic options available in clinical practice remain predominantly supportive, highlighting the urgent need for innovative treatments. In this study, we investigated the potential protective benefits of extracellular vehicles from the probiotic strain Lactiplantibacillus plantarum (LpEVs) in ALI mouse model. We revealed that LpEVs administration attenuated LPS-induced ALI, as evidenced by reduced lung pathology, decreased inflammatory markers, and mitigated ferroptosis. In vitro experiments demonstrated that LpEVs restrained ferroptosis and promoted a shift towards an anti-inflammatory macrophage phenotype. Moreover, LpEVs increased the expression of NRF2, resulting in the promotion of HO1 and strengthening anti-ferroptotic System Xc-/GPX4 axis. Our analysis revealed that LpEVs alleviated ALI through the suppression of macrophages ferroptosis by delivering cbn-let-7 targeting ferroptosis-related gene Acsl4. These findings propose LpEVs as a promising therapeutic approach for preventing and treating ALI, highlighting the potential of leveraging probiotic-derived biomolecules to develop novel therapeutic strategies.

The Microbiota-Human Health Axis

Trillions of microorganisms play a pivotal role in maintaining health and preventing disease in humans. Their presence influences daily life, habits, energy levels, and pathologies. The present narrative review synthesized recent studies of microbial diversity across organ systems. The composition of the microbiota regulates the intestinal barrier, modulates the immune response, influences metabolism, and produces essential compounds such as short-chain fatty acids and neurotransmitters. Dysbiosis is associated with numerous pathologies, including metabolic, autoimmune, neurodegenerative, and cardiovascular diseases. The microbiota is key to maintaining physiological balance and reducing disease risk. Therapeutic interventions, such as probiotics, prebiotics, postbiotics, and microbiome transplantation, offer promising perspectives in restoring microbial homeostasis and preventing chronic diseases.

Ligilactobacillus salivarius regulating translocation of core bacteria to enrich mouse intrinsic microbiota of heart and liver in defense of heat stress

The aim of this study was to elucidate the intrinsic microbiota residing in the heart and liver, which was enriched with Ligilactobacillus salivarius supplementation and its roles in defending anti-oxidation of heat stress. The specific pathogen free (SPF) mice were employed to perform the study. Genomic sequencing showed that the intrinsic microbes in the heart and liver of SPF mice, which were primarily of the genera Burkholderia and Ralstonia, functioned in organic metabolism, environmental information processing, cellular processes, and genetic information processing. Lactobacillus sp. were found in the liver but not in the heart. The heart had a lower bacterial abundance than the liver. A culturomic assay of the heart flushing liquid indicated that the dominant species of bacteria were Ralstonia pickettii, Ralstonia sp._3PA37C10, Ralstonia insidiosa, Burkholderia lata, unclassified _g_ Ralstonia, and unclassified _p_ Pseudomonadota. Intrinsic bacteria exist in the heart due to their inhibitory action against pathogenic Escherichia coli. After, the mice were supplemented with Ligilactobacillus salivarius to optimize the microbiota levels. The dominant bacterial phyla in the liver and heart were Bacillota, Bacteroidota, Pseudomonadota, Thermodesulfobacteriota, andActinomycetota, which comprised 98.2% of total bacteria. The genus Lactobacillus was also abundant. Core bacteria such as Lactobacillus reuteri are translocated from the intestine to the heart and liver. The enriched bacterial composition up-regulated anti-oxidation capacities in the heart and liver. The levels of reactive oxygen species and superoxide dismutase (SOD) were significantly improved compared to those in control (P < 0.01). In conclusion, intrinsic bacteria present in the heart and liver alleviate infection by pathogens, environmental and genetic information processing, and cellular processes during heat stress exposure. Diet with Ligilactobacillus salivarius supplementation regulated the translocation of core bacteria to the heart and liver, improved bacterial composition, and induced a higher anti-oxidative capacity under heat stress.

SARS-CoV-2 infectivity can be modulated through bacterial grooming of the glycocalyx

The gastrointestinal (GI) tract is a site of replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and GI symptoms are often reported by patients. SARS-CoV-2 cell entry depends upon heparan sulfate (HS) proteoglycans, which commensal bacteria that bathe the human mucosa are known to modify. To explore human gut HS-modifying bacterial abundances and how their presence may impact SARS-CoV-2 infection, we developed a task-based analysis of proteoglycan degradation on large-scale shotgun metagenomic data. We observed that gut bacteria with high predicted catabolic capacity for HS differ by age and sex, factors associated with coronavirus disease 2019 (COVID-19) severity, and directly by disease severity during/after infection, but do not vary between subjects with COVID-19 comorbidities or by diet. Gut commensal bacterial HS-modifying enzymes reduce spike protein binding and infection of authentic SARS-CoV-2, suggesting that bacterial grooming of the GI mucosa may impact viral susceptibility.IMPORTANCESevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for coronavirus disease 2019, can infect the gastrointestinal (GI) tract, and individuals who exhibit GI symptoms often have more severe disease. The GI tract's glycocalyx, a component of the mucosa covering the large intestine, plays a key role in viral entry by binding SARS-CoV-2's spike protein via heparan sulfate (HS). Here, using metabolic task analysis of multiple large microbiome sequencing data sets of the human gut microbiome, we identify a key commensal human intestinal bacteria capable of grooming glycocalyx HS and modulating SARS-CoV-2 infectivity in vitro. Moreover, we engineered the common probiotic Escherichia coli Nissle 1917 (EcN) to effectively block SARS-CoV-2 binding and infection of human cell cultures. Understanding these microbial interactions could lead to better risk assessments and novel therapies targeting viral entry mechanisms.

Elucidating Causal Relationships Among Gut Microbiota, Human Blood Metabolites, and Knee Osteoarthritis: Evidence from a Two-Stage Mendelian Randomization Analysis

Background: Although previous observational studies suggest a potential association between gut microbiota (GM) and knee osteoarthritis (KOA), the causal relationships remain unclear, particularly concerning the role of blood metabolites (BMs) as potential mediators. Elucidating these interactions is crucial for understanding the mechanisms underlying KOA progression and may inform the development of novel therapeutic strategies. Objective: This study aimed to determine the causal relationship between GM and KOA and to quantify the potential mediating role of BMs. Methods: Instrumental variables (IVs) for GM and BMs were retrieved from the MiBioGen consortium and metabolomics genome-wide association studies (GWAS) databases. KOA-associated single-nucleotide polymorphisms were sourced from the FinnGen consortium. Inverse-variance weighted approach was utilized as the main analytical method for Mendelian randomization (MR) analysis, complemented by MR-Egger, simple mode, weighted mode, and weighted median methods. The causal relationships between GM, BMs, and KOA were sequentially analyzed by multivariate MR. False discovery rate correction was applied to account for multiple comparisons in the MR results. Sensitivity analyses and reverse MR analysis were also conducted to verify the reliability of the findings. Finally, a two-step approach was employed to determine the proportion of BMs mediating the effects of GM on KOA. Results: MR analysis identified seven gut microbial species that are causally associated with KOA. Additionally, MR analysis of 1091 BMs and 309 metabolite ratios revealed 13 metabolites that influence the risk of KOA. Through two-step analysis, three BMs were identified as mediators of the effects of two GMs on KOA. Among them, 6-hydroxyindole sulfate exhibited the highest mediation percentage (10.26%), followed by N-formylanthranilic acid (6.55%). Sensitivity and reverse causality analyses further supported the robustness of these findings. Conclusion: This research identified specific GMs and BMs that have a causal association with KOA. These findings provide critical insights into how GM may influence KOA risk by modulating specific metabolites, which could be valuable for the targeted treatment and prevention of KOA.

The impact of early-life and prolonged antibiotics exposure on 78 common diseases: Evidence from epidemiology

BACKGROUND

Early-life and prolonged exposure to antibiotics has been associated with various health issues. This study aimed to explore the relationship between early-life antibiotic exposure and different health outcomes from the perspective of epidemiology.

METHODS

Using electronic hospital records, questionnaire data and genotype information from the UK Biobank, this study analysed 158 391 individuals with early-life and prolonged antibiotics exposure to investigate its association with 78 common diseases. After adjusting for covariates, we conducted an observational study to explore the relationships between antibiotic use and various diseases. Subsequently, a genome-wide association analysis was performed on early-life and prolonged antibiotics use, and eight Mendelian randomization methods were applied with instrumental variables to account for confounding factors and explore potential causal relationships.

RESULTS

In our observational study involving 78 common diseases, our findings revealed significant associations between exposure to antibiotics during early life and 42 diseases, after correcting the false discovery rate. Among these, 8 diseases demonstrated causal evidence. These diseases include type-2 diabetes (odds ratio [OR] with 95% confidence interval [95% CI] = 1.27 [1.18, 1.36], P = 4.8 × 10-11), depression (OR = 1.77 [1.67, 1.89], P = 2.2 × 10-72), inflammatory bowel disease (OR = 1.28 [1.14, 1.45], P = 6.2 × 10-5), polymyalgia rheumatica (OR = 1.28 [1.07, 1.53], P = 6.4 × 10-3), giant cell arteritis (OR = 1.55 [1.12, 2.14], P = 7.5 × 10-3), sciatica (OR = 1.54 [1.35, 1.76], P = 8.3 × 10-11), cystitis (OR = 1.51 [1.31, 1.74], P = 8.1 × 10-9) and bronchiectasis (OR = 2.70 [2.37, 3.06], P = 9.7 × 10-52).

CONCLUSION

This study revealed the enduring and detrimental effects of prolonged antibiotic usage during early life, which can potentially result in the development of diseases across multiple bodily systems.

Integrated network pharmacological analysis and multi-omics techniques to reveal the mechanism of polydatin in the treatment of silicosis via gut-lung axis

Silicosis is a pulmonary disease characterized by inflammation and progressive fibrosis. Previous studies have shown that polydatin (PD) has potential biological activity in key signaling pathways regulating inflammation and apoptosis. To investigate the effect of PD on rats with silicosis, this study used network pharmacology and molecular docking methods to determine the target of PD treatment for silicosis. The therapeutic effect of PD on silicosis was confirmed by measuring the lung injury score, hydroxyproline content, and mRNA expression levels of key targets. In addition, metagenomic sequencing and gas chromatography-mass spectrometry were used to determine the gut microbiota composition and targeted metabolomics analysis, respectively. The results showed that PD could inhibit the expression of inflammation-related indexes and apoptosis-related indexes at protein and mRNA levels. PD also regulates the diversity of the intestinal flora and the content of short-chain fatty acids. In conclusion, the current data suggest that PD has a protective effect against silica-induced lung injury and plays a protective role in regulating intestinal flora diversity and short-chain fatty acid levels through the gut-lung axis.

Unveiling the hidden impact of long-term metal-rich volcanic pollution on male reproductive functions using isotope metallomics

Volcanic eruptions release particles in a range of sizes that can chronically affect the health of communities within tens of kilometers of the volcano. Many years after an eruption, resuspension of volcanic ash can exacerbate the health impact of primary eruptive events. So far, our global understanding of the health effects triggered by chronic exposure to volcanic particles at the whole-body scale is limited. Recently, it has been shown that mice chronically exposed to metal-rich volcanic ash deposits present metallome deregulations associated with pathophysiological changes. These deregulations preferentially impact the reproductive functions, questioning about the impact of ash on fertility. This work aims to further assess the mechanisms driving the ash-related fertility disorders and develop predictive biomarkers. For that, elemental concentrations and Cu-Zn-Fe isotope measurements coupled to metabolomic, proteomic and transcriptomic analyses were measured in blood, liver and two organs of the male reproductive system (testis, seminal vesicle). The samples were collected on wild-type and mice exposed over two months to volcanic ash. Mice exposed to ash are characterized by (i) significant metallomic deregulations, (ii) higher oxidative stress correlating with isotopic variations of redox-sensitive elements and (iii) testicular and hepatic alterations, marked by gains in organ mass, hepatic lipid accumulation and circulating bile acids overload, all of which might exacerbate testicular defects. Together, these results demonstrate that prolonged exposure to metal-rich ash is a threat for male reproduction and that investigating redox-sensitive isotopes might help identifying early signs of oxidative stress-related testicular injuries, with future implications for hepato-testicular disease prevention.

Tannic acid mitigates salmonella-induced lung injury via gut-lung axis in broilers

Tannic acid (TA), a polyphenolic compound derived from plants, exhibits anti-inflammatory, antibacterial, antiviral, and antioxidant biological activities. Salmonella, a prevalent foodborne pathogen, poses a significant threat to poultry, resulting in considerable economic losses for the animal husbandry industry. In this study, we investigated the protective effects of TA against lung and intestinal injuries induced by a transient Salmonella infection in broilers. After a ten-day infection period, although Salmonella was not detected in the intestinal content of broilers, the infected broilers exhibited reduced body weight and compromised intestinal barrier function. Salmonella infection facilitated the growth of detrimental bacteria in the lungs and ileums, triggering an inflammatory response. TA inhibited the pathogen's colonization in the lungs and reduced serum levels of lipopolysaccharide (LPS) as well as lung levels of myeloperoxidase (MPO). Moreover, TA down-regulated the expression of pro-inflammatory cytokines and hindered the polarization of M1 macrophages in the lungs. In summary, TA mitigates Salmonella-induced lung inflammation and immune imbalance by its anti-inflammatory, antioxidant and antibacterial properties in broilers.

A genome-wide cross-trait analysis characterizes the shared genetic architecture between lung and gastrointestinal diseases

Lung and gastrointestinal diseases often occur together, leading to more adverse health outcomes than when a disease of one of these systems occurs alone. However, the potential genetic mechanisms underlying lung-gastrointestinal comorbidities remain unclear. Here, we leverage lung and gastrointestinal trait data from individuals of European, East Asian and African ancestries, to perform a large-scale genetic cross trait analysis, followed by functional annotation and Mendelian randomization analysis to explore the genetic mechanisms involved in the development of lung-gastrointestinal comorbidities. Notably, we find significant genetic correlations between 27 trait pairs among the European population. The highest correlation is between chronic bronchitis and peptic ulcer disease. At the variant level, we identify 42 candidate pleiotropic genetic variants (3 of them previously uncharacterized) in 14 trait pairs by integrating cross-trait meta-analysis, fine-mapping and colocalization analyses. We also find 66 candidate pleiotropic genes, most of which were enriched in immune or inflammatory response-related activities. Causal inference approaches result in 4 potential lung-gastrointestinal associations. Introducing the gut microbiota as a variable establishes a relationship between the genus Parasutterella, gastro-oesophageal reflux disease and asthma. In summary, our findings highlight the genetic relationship between lung and gastrointestinal diseases, providing insights into the genetic mechanisms underlying the development of lung gastrointestinal comorbidities.

Beyond the pill: incrimination of nuclear factor-kappa B and their targeted phytomedicine for pulmonary fibrosis

Pulmonary fibrosis (PF) is a slow and irreparable damage of the lung caused by the accumulation of scar tissue, which eventually results in organ dysfunction and fatality from gas exchange failure. One of the extensively studied inflammatory pathways in PF is the NF-κB signalling pathway, which is reportedly involved in epithelial-mesenchymal transition, myofibroblast differentiation, and other cellular processes. Additionally, studies have evidence that NF-κB signalling pathways can be employed as a potential target for developing therapeutic agents against PF. In the current scenario, FDA-approved drugs, nintedanib and pirfenidone, have been used for the treatment of PF with potential side effects. Recently, the usage of bioactive compounds has attracted attention in the treatment of PF. This review focuses on the involvement of the NF-κB signalling pathway in PF and the significance of phytocompounds in regulating the NF-κB pathway. Both the in vitro and in vivo studies reveal that NF-κB-targeted plant-based bioactive compounds significantly ameliorate the PF condition as well as improve the health condition. Databases such as Scopus, PubMed, and Web of Science were used to conduct literature surveys and compile data on all the bioactive compounds. In conclusion, the plant-derived bioactive compounds are potent enough to target the NF-κB with its biological properties, and this could be a highly effective therapeutic strategy for PF in the future.

Gut bacterial lactate stimulates lung epithelial mitochondria and exacerbates acute lung injury

Acute respiratory distress syndrome (ARDS) is an often fatal critical illness where lung epithelial injury leads to intrapulmonary fluid accumulation. ARDS became widespread during the COVID-19 pandemic, motivating a renewed effort to understand the complex etiology of this disease. Rigorous prior work has implicated lung endothelial and epithelial injury in response to an insult such as bacterial infection; however, the impact of microorganisms found in other organs on ARDS remains unclear. Here, we use a combination of gnotobiotic mice, cell culture experiments, and re-analyses of a large metabolomics dataset from ARDS patients to reveal that gut bacteria impact lung cellular respiration by releasing metabolites that alter mitochondrial activity in lung epithelium. Colonization of germ-free mice with a complex gut microbiota stimulated lung mitochondrial gene expression. A single human gut bacterial species, Bifidobacterium adolescentis, was sufficient to replicate this effect, leading to a significant increase in mitochondrial membrane potential in lung epithelial cells. We then used genome sequencing and mass spectrometry to confirm that B. adolescentis produces L -lactate, which was sufficient to increase mitochondrial activity in lung epithelial cells. Finally, we found that serum lactate was significantly associated with disease severity in patients with ARDS from the Early Assessment of Renal and Lung Injury (EARLI) cohort. Together, these results emphasize the importance of more broadly characterizing the microbial etiology of ARDS and other lung diseases given the ability of gut bacterial metabolites to remotely control lung cellular respiration. Our discovery of a single bacteria-metabolite pair provides a proof-of-concept for systematically testing other microbial metabolites and a mechanistic biomarker that could be pursued in future clinical studies. Furthermore, our work adds to the growing literature linking the microbiome to mitochondrial function, raising intriguing questions as to the bidirectional communication between our endo- and ecto-symbionts.

Exploring the impact of gut microbiota-mediated regulation of exosomal miRNAs from bone marrow mesenchymal stem cells on the regulation of bone metabolism

BACKGROUND

Osteoporosis, which is a prevalent metabolic bone disease, is closely associated with imbalances in the gut microbiota.

METHODS

The ovaries of female 6-month-old Sprague-Dawley rats were surgically removed to induce osteoporosis. Subsequently, 16S rRNA sequencing was employed to characterize the gut microbiota in the osteoporotic rats. Bone marrow mesenchymal stem cells (BMSCs) were isolated from osteoporotic rats and cultured separately, and their osteogenic and adipogenic differentiation was observed. Furthermore, exosomes were extracted from these cells, and miRNA sequencing was performed on the exosomes to identify key miRNAs. Osteoporotic rats were then treated with a member of the gut microbiota, and changes in the osteogenic and adipogenic differentiation of BMSCs were observed.

RESULTS

In our investigation, we observed altered proportions of Firmicutes and Bacteroidetes in the guts of ovariectomized rats, which contributed to dysbiosis and subsequent changes in intestinal permeability. The BMSCs exhibited disrupted osteogenic/adipogenic differentiation, which was associated with structural damage to bones. Through the isolation of exosomes from BMSCs and subsequent miRNA analysis, we identified miR-151-3p and miR-23b-3p as potential pivotal regulators of bone metabolism. Furthermore, through 16S rRNA sequencing, we identified g_Ruminococcus and its marked capacity to ameliorate the imbalance in BMSC osteogenic/adipogenic differentiation. Intervention with g_Ruminococcus demonstrated promising outcomes, mitigating bone loss and structural damage to the tibia and femur in ovariectomized rats.

CONCLUSIONS

These findings highlight the significant role of g_Ruminococcus in alleviating osteoporosis induced by estrogen deficiency, suggesting its therapeutic potential for addressing postmenopausal osteoporosis through the targeted modulation of BMSC-derived exosomal miR-151-3p and miR-23b-3p.

Exploring the Causal Relationship Between Gut Microbiota and Pulmonary Artery Hypertension: Insights From Mendelian Randomization

BACKGROUND

Research into the "gut-lung" axis links gut microbiota to pulmonary artery hypertension (PAH). However, the mechanisms by which gut microbiota influence PAH remain unclear. We aimed to investigate the causal relationship between the gut microbiota and PAH using Mendelian randomization analysis, identify key microbiota and metabolites, and explore the regulatory role of associated genes in PAH pathogenesis.

METHODS AND RESULTS

We examined the association between gut microbiota taxa and PAH using inverse variance weighted 2-sample Mendelian randomization analysis, Mendelian randomization-Egger, weighted median, and weighted mode methods. Additionally, we identified PAH-regulating genes in the intestinal microbiome using bioinformatics tools and validated their expression levels in the lung tissue of hypoxia-induced PAH mice models by quantitative reverse transcription polymerase chain reaction. Eleven gut microbiota taxa were associated with PAH. The order Clostridiales and genera Eubacterium fissicatena group, Lachnospiraceae UCG004, and Ruminococcaceae UCG002 were positively associated with PAH, whereas the order Bifidobacteriales; family Bifidobacteriaceae; and genera Eubacterium eligens group, Sutterella, Methanobrevibacter, Sellimonas, and Tyzzerella3 were negatively associated with PAH, with some exhibiting bidirectional causality. These microbiota modulate 24 metabolites, including palmitoylcholine, oleoylcholine, and 3,7-dimethylurate, to influence PAH. Hypoxia-induced PAH mice had significantly downregulated 1,4,5-trisphosphate receptor type 2, degrading enzyme, nuclear receptor-interacting protein 1, and growth factor-binding protein 1 in lung tissues, indicating their potential role in PAH regulation.

CONCLUSIONS

These findings suggest that gut microbiota composition and associated metabolites contribute to PAH development by regulating lung tissue gene expression. Our findings have implications for advancing gut microbiota-based PAH diagnostic technologies and targeted therapies.

The interaction between various food components and intestinal microbiota improves human health through the gut-X axis: independently or synergistically

Food contains various components that improve health by affecting the gut microbiota, primarily by modulating its abundance or altering its diversity. Active substances in food have different effects on the gut microbiota when they act alone or in synergy, resulting in varying impacts on health. The bioactive compounds in food exert different effects on various gut microbiota through multiple pathways, thereby delaying or preventing different kinds of disease. The combination of two or more active compounds may have a synergistic effect, which can more effectively alter the gut microbiota and alleviate diseases through the microbiota-gut-organ axis. According to reports, multiple different food components have similar effects, some of which have been shown to have a synergistic effect on the gut microbiota to promote health. However, there is currently no systematic review of its synergistic effects and mechanisms. There may be more compounds with synergistic effects that have not yet been discovered, while their mechanisms of synergy and ways of impacting host health through the gut microbiota deserve further investigation. The purpose of this review is to systematically summarize the effects of different food components on intestinal flora and health, and further analyze the potential synergies between different food components. PubMed and Google Scholar databases were searched in this review.

The Causal Relationship Between Gut and Skin Microbiota and Chronic Obstructive Pulmonary Disease:A Bidirectional Two-Sample Mendelian Randomization Analysis

Background

Recently, numerous studies have explored the potential impact of gut microbiota on Chronic Obstructive Pulmonary Disease (COPD). However, the causal relationship between skin microbiota and COPD, as well as the differences and similarities between the relationships of gut microbiota and COPD, has not been thoroughly studied.

Methods

We conducted a comprehensive two-sample Mendelian randomization (MR) analysis to investigate the relationships between gut and skin microbiota and COPD. The inverse variance weighted (IVW) method was used as the primary approach. MR-Egger, weighted median, and MR-PRESSO methods were used as supplementary approaches. Various sensitivity and stability analyses were conducted to validate the results. Genetic variations of gut microbiota were obtained from the FR02 cohort study. Genetic variations of skin microbiota were derived from the KORA FF4 and PopGen cohorts, with a total of 1,656 skin samples. GWAS data for COPD were obtained from the FinnGen consortium, including 18,266 COPD cases and 311,286 controls from European cohorts.

Results

The results of IVW method of MR analysis showed that 10 gut microbiotas and 4 skin microbiotas were negatively associated with COPD [p < 0.05, odds ratio (OR) < 1]; 3 gut microbiotas and 6 skin microbiotas were positively associated with COPD (p < 0.05, OR > 1). None of them were heterogeneous or horizontally pleiotropic (p > 0.05) or reverse causality.

Conclusion

This study revealed the causal relationships between gut and skin microbiota and COPD, offering fresh perspectives for the prevention, diagnosis, and management of COPD.

Research status of the relationship between microecological imbalance and lung cancer

Microecology refers to the ecosystem formed by human and microbial communities in the process of co-evolution, the microecological imbalance is associated with occurrence and development of multiple diseases, including lung cancer. In this review, we detailedly summarized the concept and roles of microecology, the relationship between microecology and human diseases, and related techniques in microecology studies. Importantly, we specially analyzed the correlations between microecology and lung cancer by focusing on gut microbiota, oral microbiota and lower respiratory tract microbiota, and further evaluated the effects of microbiota dysbiosis on chemotherapy and immunotherapy efficacy in lung cancer. At last, we discussed the potential mechanisms by which dysregulated microbiota promotes the genesis and development of lung cancer. Microecology-centered detection and intervention will improve the early diagnosis of lung cancer and provide new targets for the treatment of lung cancer.

Fungal microbiota in COPD patients during exacerbations

Acute exacerbations of chronic obstructive pulmonary disease (COPD) results in increased mortality and can be triggered by a range of factors, including microorganisms. Very little studies have examined the role of fungi and fungal diversity in COPD patients. The aim of the study was to determine the role of Candida in COPD during an exacerbation. Oral swabs, sputum, feces and whole blood samples were collected from the AECOPD patients and control group. Mycological and serological analysis were performed. Yeast were statistically significantly more often isolated from the AECOPD group (97.06%) than from the control group (26.32%). 7 species were isolated from the AECOPD, and 3 from the control group. Dominated Candida albicans followed by C. tropicalis. α-diversity was much greater in AECOPD patients than in controls. β-diversity was also assessed. A much higher level of antimycotic resistance was observed in isolates from the AECOPD group, which affects the effectiveness of therapy. Serological tests showed twice the frequency of positive results in the AECOPD group. The mycobiota of AECOPD patients is numerically and taxonomically richer than controls, including species less frequently recorded in humans. Our research confirms that fungal mycobiota may be a potential factor influencing the development of exacerbations and progression of COPD.

Interaction, diagnosis, and treatment of lung microbiota-NLRP3 inflammasome-target organ axis in sepsis

Sepsis is defined as a life-threatening condition caused by a dysregulated host response to infection, leading to multi-organ dysfunction, and representing a significant global health burden. The progression of sepsis is closely linked to disruptions in lung microbiota, including bacterial translocation, impaired barrier function, and local microenvironmental disturbances. Conversely, the worsening of sepsis exacerbates lung microbiota imbalances, contributing to multi-organ dysfunction. Recent culture-independent microbiological techniques have unveiled the complexity of the respiratory tract microbiome, necessitating a reassessment of the interactions between the host, microbes, and pathogenesis in sepsis. This review synthesizes current insights into the causes of microbiota dysbiosis and the regulatory mechanisms of the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome, as well as their interactions during sepsis and sepsis-induced organ dysfunction. In addition, we summarize novel diagnostic and therapeutic approaches from the current study that may offer promising prospects for the management of sepsis.

Vitronectin regulates lung tissue remodeling and emphysema in chronic obstructive pulmonary disease

Vitronectin (VTN) is an important extracellular matrix protein in tissue remodeling, but its role in chronic obstructive pulmonary disease (COPD) is unknown. We show that VTN regulates tissue remodeling through urokinase plasminogen activator (uPA) signaling pathway in COPD. In human COPD airways and bronchoepithelial cells and the airways of mice with cigarette smoke (CS)-induced experimental COPD, VTN protein was not changed, but downstream uPA signaling was altered (increased plasminogen activator inhibitor-1) that induced collagen and airway remodeling. In the parenchyma, VTN levels were decreased, uPA signaling pathway differentially altered and collagen reduced in lung fibroblasts from human and lung parenchyma in experimental COPD. Vtn inhibition with siRNA in mouse fibroblasts altered uPA signaling increased matrix metalloproteinase-12, and reduced collagen, whereas over-expression restored collagen production after CS extract challenge. Vtn-/- and Vtn small interfering RNA-treated mice had exaggerated inflammation, emphysema, and impaired lung function compared with controls with CS-induced COPD. Restoration of VTN in the parenchyma may be a therapeutic option for emphysema and COPD.

Efficacy of acupuncture for stroke-associated pneumonia: a systematic review and meta-analysis

Objectives

This study aims to systematically evaluate the efficacy of acupuncture on stroke-associated pneumonia (SAP).

Methods

English and Chinese databases were searched from their inception until 15 March 2024 to collect randomized controlled trials (RCTs). The risk of bias was assessed using Cochrane collaboration tools. RevMan 5.4.0 software was used to analyze the included studies, and the Grades of Recommendations, Assessment, Development, and Evaluation (GRADE) assessment was used to evaluate the quality of the study outcomes.

Results

16 studies involving 1,125 patients were included in this meta-analysis. Compared with the control group, the results showed that acupuncture significantly improved the effective rate [RR = 1.20, 95% CI (1.13, 1.27), P < 0.00001] and reduced the level of white blood cells (WBC) [MD = -6.52, 95% CI (-8.31, -4.73), P < 0.00001], C reactive protein (CRP) [MD = -6.50, 95% CI (-9.97, -3.03), P = 0.0002], neutrophil percentage (Neu%) [MD = -6.66, 95% CI (-8.96, -4.36), P < 0.00001], and procalcitonin (PCT) [MD = -0.81, 95% CI (-1.21, -0.40), P < 0.0001]. Additionally, acupuncture therapy shortened the duration of coughing [MD = -3.22, 95% CI (-4.73, -1.72), P < 0.0001], duration until disappearance of rales [MD = -3.99, 95% CI (-6.44, -1.54), P = 0.001], and duration of antibiotic use [MD = -4.51, 95% CI (-5.46, -3.57), P < 0.00001]. It also reduced the clinical pulmonary infection score (CPIS) [MD = -1.71, 95% CI (-2.71, -0.71), P = 0.0008] and National Institute of Health Stroke Scale (NIHSS) [MD = -3.93, 95% CI (-5.78, -2.09), P < 0.00001]. Moreover, acupuncture therapy increased the forced vital capacity (FVC) [MD = 0.46, 95% CI (0.02, 0.89), P = 0.04] and Forced Expiratory Volume in One Second (FEV1) [MD = 0.49, 95% CI (0.14, 0.84), P = 0.006].

Conclusion

This study found that acupuncture has a positive effect in treating SAP. However, owing to the low-quality evidence, more rigorous studies are needed in the coming years to confirm these findings.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023462846, identifier CRD42023462846.

Rosa roxburghii Fermentation Broths Attenuate Bleomycin-Induced Pulmonary Fibrosis by Activating the Nrf2/HO-1/NQO1 Signaling Pathway and Modulating Gut Microbiota

Pulmonary fibrosis (PF) is a chronic and progressive lung disease, and oxidative stress plays a critical role in its pathogenesis. Rosa roxburghii Tratt, known for its anti-inflammatory and antioxidant properties, has been shown to alleviate fibrosis. This study aimed to explore whether two Rosa roxburghii fermentation broths (RRFBs) (with different proportions) could attenuate bleomycin (BLM)-induced PF in mice and to elucidate the molecular mechanisms. The results revealed that RRFBs reduced structural lung damage, collagen deposition, and lung inflammation. RRFBs also suppressed fibrotic markers (Collagen I, Vimentin, and α-SMA) while enhancing epithelial marker E-cadherin expression. Additionally, RRFBs alleviated BLM-induced oxidative stress and apoptosis by activating the Nrf2/HO-1/NQO1 signaling pathway and facilitating Nrf2 nuclear translocation. Furthermore, RRFBs attenuated the BLM-induced changes in the gut microbiota; in particular, they decreased the abundance of the pathogenic bacterium Proteus and increased the abundance of the probiotics Ileibacterium and Dubosiella. Spearman correlation analysis revealed a strong association between oxidative stress inhibition and gut microbiota composition. These results indicated that RRFBs could exert lung-protective effects by inhibiting oxidative stress and alleviating intestinal disturbances.

Profiling of the gut, skin and nasal microbiotas revealed clinically relevant microbial taxa from children with allergies: a pilot study

Background

A reduction in biodiversity and alterations in the microbiota composition are relevant to allergic diseases. However, combined analyses of the skin, nasal and gut microbiotas are lacking in the literature. In addition, in previous studies, microbiota were detected mainly by V3-V4 sequencing, but other sequences might be missed with this technique.

Methods

In this case-control study, we enrolled 3-12-year-old children with allergic rhinitis combined with atopic dermatitis and food allergy (AR-AD-FA group), children with allergic rhinitis only (AR-only) and healthy controls (HC group). We employed full-length 16S rRNA gene amplification and sequencing for the detection of gut, nasal and skin microbiota.

Results

Samples with an average sequence length of 1,459 bp were obtained in this study. Significant differences in beta diversity in the three compartments were found between the disease groups and the HC group. Differentially expressed genera were present mainly in the gut compartment. Peptoniphilus, Prevotella and Anaerococcus were abundant in the gut in the disease groups. Specifically, Streptomyces, Thermus and Pseudomonas showed differential expression in both the nasal and skin compartments of children in the disease groups.

Conclusion

Some meaningful differences in the abundance of some microbiota from the three compartments were observed between the disease groups and the HC group. These findings could provide new insights into the prevention and treatment of allergic diseases through the regulation of specific microbiota in the future.

A gut Eggerthella lenta-derived metabolite impairs neutrophil function to aggravate bacterial lung infection

The composition of the gut microbiota in patients with bronchiectasis has been proven to be distinct from that of healthy individuals, and this disrupted gut microbiota can exacerbate lung infections. However, the responsible microbes and mechanisms in the "gut-lung" axis in bronchiectasis remain unknown. Here, we report that Eggerthella lenta was enriched in the gut, and taurine ursodeoxycholic acid (TUDCA) was enriched in both the guts and sera of patients with bronchiectasis, with both being associated with disease severity. Fecal microbiota transfer from patients with bronchiectasis as well as administration of E. lenta independently exacerbated pulmonary Pseudomonas aeruginosa infections in murine models. E. lenta-associated TUDCA bound adenosine monophosphate-activated protein kinase (AMPK) within neutrophils and interfered with the interaction between liver kinase B1 and AMPK, with a consequential decrease in AMPK phosphorylation. This ultimately reduced ATP production in neutrophils, inhibited their function, and compromised P. aeruginosa elimination from the lung, aggravating tissue injury. Metformin treatment improved disease severity and outcome in the mouse models. In sum, the gut bacterium E. lenta raises the stakes of bacterial lung infection because it causes dysfunction of neutrophils circulated from serum to lung via the metabolite TUDCA. Interventions targeting E. lenta or AMPK phosphorylation may serve as adjunctive strategies to complement existing approaches for managing chronic pulmonary infection in bronchiectasis and other chronic respiratory disease states.

Enterotoxigenic Escherichia coli as a Modulator of the Entero-Pulmonary Axis in Piglets: Impacts on the Microbiota and Immune Responses

The high prevalence of enterotoxigenic Escherichia coli (ETEC) in nondiarrheic piglets contributes to its rapid spread; however, few studies have explored the effects of latent gastrointestinal pathogens on animal health. Therefore, using high-throughput sequencing approaches, we explored changes in entero-pulmonary microbiota and immune gene expression in healthy, asymptomatic, and diarrheic piglets. As expected, bacterial communities were less diverse in the respiratory tract than in the gut, with a site-specific composition that was more stable in the gut and highly variable in the lung among the investigated animals. Although no significant changes in diversity rates were seen based on ETEC-carrier state, our findings suggest that ETEC's presence can cause dysbiosis in the gut and lung in asymptomatic and diarrheic piglets, reinforcing the crosstalk in the entero-pulmonary axis. We also identified potential bacterial biomarkers that can be used to monitor piglet health: Sphaerochaeta, Bacteroides, Butyricoccus, and Blautia were highly represented in the gut, while Streptococcus and Prevotellaceae NK3B31 group were enriched in the lungs of healthy piglets. In addition, most metabolic pathways predicted in the bacterial communities were shared despite the ETEC-carrier state, with differences observed only in the gut microbiota, suggesting that ETEC's presence may impact substrate utilization. Finally, we observed shifts in the intestinal expression of tff2 and cd36 immune markers between healthy and diarrheic piglets, which might suggest their use as prognostic markers for postweaning diarrhea (PWD). Although the effect remains unclear, the ETEC-carrier state also altered the transcription of other markers locally (in the gut and lung) and systemically, which corroborates the shared mucosal immunity in the entero-pulmonary axis in piglets. Overall, despite limitations regarding sample size, our findings give clues about the entero-pulmonary dynamics in piglets in the presence of a gastrointestinal pathogen, representing a starting point for future research on this axis for veterinary purposes.

Advances in research on gut microbiota and allergic diseases in children

Epidemiological studies indicate a rising prevalence of allergic diseases, now recognized as a major global public health concern. In children, the progression of these diseases often follows the "atopic march," beginning with eczema, followed by food allergies, allergic rhinitis, and asthma. Recent research has linked gut microbiota dysbiosis to the development of allergic diseases in children. The gut microbiota, a crucial component of human health, plays a vital role in maintaining overall well-being, highlighting its potential in preventing and modifying the course of allergic diseases. This review examines the relationship between childhood allergic diseases and gut microbiota, drawing on the latest evidence. We first elaborated the concepts of allergic diseases and gut microbiota, followed by a discussion of the developmental trajectory of the gut microbiota in healthy children. This review further explored the richness, diversity, and composition of the gut microbiota, as well as specific microbial taxa associated with allergic disease. Lastly, we discussed the current status and future potential of probiotic interventions in managing pediatric allergic diseases.

The relationship between gut and nasopharyngeal microbiome composition can predict the severity of COVID-19

Coronavirus disease 2019 (COVID-19) is a respiratory illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that displays great variability in clinical phenotype. Many factors have been described to be correlated with its severity, and microbiota could play a key role in the infection, progression, and outcome of the disease. SARS-CoV-2 infection has been associated with nasopharyngeal and gut dysbiosis and higher abundance of opportunistic pathogens. To identify new prognostic markers for the disease, a multicentre prospective observational cohort study was carried out in COVID-19 patients divided into three cohorts based on symptomatology: mild (n = 24), moderate (n = 51), and severe/critical (n = 31). Faecal and nasopharyngeal samples were taken, and the microbiota was analysed. Linear discriminant analysis identified Mycoplasma salivarium, Prevotella dentalis, and Haemophilus parainfluenzae as biomarkers of severe COVID-19 in nasopharyngeal microbiota, while Prevotella bivia and Prevotella timonensis were defined in faecal microbiota. Additionally, a connection between faecal and nasopharyngeal microbiota was identified, with a significant ratio between P. timonensis (faeces) and P. dentalis and M. salivarium (nasopharyngeal) abundances found in critically ill patients. This ratio could serve as a novel prognostic tool for identifying severe COVID-19 cases.

Study of the microenvironment of the lung flora in female lung adenocarcinoma patients: from benign lesions to invasive lung adenocarcinomas

BACKGROUND

The number of female lung adenocarcinoma patients is increasing annually, but these patients are difficult to diagnose in the early stage without obvious clinical symptoms, leading to late-stage diagnoses and poor outcomes. Recent studies have shown that the lung microbiota is closely related to the occurrence and development of lung cancer, especially the characteristic changes in the lung microbiota of lung cancer patients, which opens a new research direction for the diagnosis and treatment of lung cancer. This study aimed to analyze the characteristics of the lung flora in different stages of female lung adenocarcinoma.

METHODS

16 S rRNA sequencing technology was used to analyze the alpha diversity, beta diversity, composition, and function of the pulmonary flora in female patients with benign lesions (n = 7), adenocarcinoma in situ (n = 16), microinvasive adenocarcinoma (n = 31), and invasive adenocarcinoma (n = 25).

RESULTS

Progression to invasive lung adenocarcinoma is correlated with reduced alpha diversity in the lung flora. Compared with the other stages, only the invasive adenocarcinoma stage had significant differences in the beta diversity of the lung flora. At the phylum and genus levels, the abundance of major flora species decreased significantly as the disease progressed to the invasive adenocarcinoma stage, whereas the abundance of Bacillus spp. increased significantly. The abundance of phenotypes with mobile elements, biofilm-forming ability, oxidative stress tolerance, parthenogenetic anaerobic properties, and pathogenicity was significantly greater in invasive adenocarcinomas. The abundance of metabolic pathways was significantly lower in invasive adenocarcinomas.

CONCLUSIONS

Invasive adenocarcinoma has a unique flora structure characterized by decreased flora diversity and abundance and an increase in specific flora (e.g., Bacillus). In terms of bacterial function, adaptability and pathogenicity increased, and metabolic pathway activity decreased.

Magnolol preserves the integrity of the intestinal epithelial barrier and mitigates intestinal injury through activation of PPAR γ in COPD rat

ETHNOPHARMACOLOGICAL RELEVANCE

Magnolia officinalis Rehder & E.H. Wilson is traditionally used in the treatment of gastrointestinal disorders, diarrhea, and cough. Its main active ingredient, magnolol, exhibits protective effects on the lungs and gastrointestinal tract, including the inhibition of inflammation in these organs.

AIM OF THE STUDY

This work aims to explore the molecular mechanism by which magnolol suppressed Chronic obstructive pulmonary disease (COPD) intestinal damage by improving the intestinal epithelial barrier.

MATERIALS AND METHODS

The study focused on investigating the mitigation effect of magnolol on intestinal injury and epithelial barrier in a COPD rat. Caco-2 cells were induced with TNF-α or IL-1β to establish the barrier injury model in order to explore the direct protective effect of magnolol on the intestinal barrier and elucidate the molecular mechanism by which it activates peroxisome proliferators-activated receptors-γ (PPARγ).

RESULTS

Magnolol significantly improves pulmonary function and tissue damage in COPD rats by inhibiting inflammation, protease imbalance, and oxidative stress. It also suppresses colon tissue damage and inflammation, and protects colon epithelial barrier function by suppressing the decline of tight junction proteins, reducing colon epithelial permeability. In Caco-2 cells, magnolol directly reduces monolayer permeability, increases TEER, and upregulates tight junction protein expression induced by TNF-α or IL-1β. Drug Affinity Responsive Target Stability (DARTS) and thermal shift assays show that magnolol effectively binds to SRC, activating PPARγ signaling in Caco-2 cells and colon tissues of COPD rats. Furthermore, magnolol enhances the binding of PPARγ and RXRα, promoting their activation and entry into the nucleus. The PPARγ inhibitor GW9662 can reverse the effects of magnolol on PPARγ activation and tight junction protein upregulation in IL-1β or TNF-α induced Caco-2 cells.

CONCLUSIONS

This work demonstrates that magnolol enhances lung and intestinal functions in COPD rats, and elucidates its mechanism of action in protecting the intestinal epithelial barrier by activating PPARγ.

Influenza a virus subtype H9N2 infection induces respiratory microbiota dysbiosis in chickens via type-I interferon-mediated mechanisms

Avian influenza virus (AIV) poses significant threats to poultry and human health. This study investigates the impact of H9N2 AIV infection on the respiratory microbiota of chickens using 16S rRNA gene sequencing. Total 48 one-day-old specific pathogen-free chickens were assigned to six groups: a control and five post-infection groups (days 1, 3, 5, 7, and 9). After a 15-day microbiota stabilization period, the infected chickens received a viral inoculum (107 TCID50/ml) via ocular, intra-nasal, and intra-tracheal routes. Tracheal and broncho-alveolar lavage samples were analyzed. Significant reductions in microbiota diversity were observed on days 5, 7, and 9 post-infection, compared to d0 controls. Permutational Multivariate Analysis of Variance confirmed significant beta diversity differences (P = 0.001) between infected and uninfected groups. The microbial shifts from d5 to d9 were marked by increased Proteobacteria, decreased Actinobacteria and Firmicutes, and a rise in Dickeya. Elevated type-I interferon (IFN-β) and viperin gene expression at d5 coincided with reduced microbiota diversity, highlighting the respiratory microbiota's role in modulating host responses to AIV H9N2 infection and suggesting potential biomarkers for respiratory dysbiosis.

The mechanism of baicalin in improving pulmonary inflammatory response and injury and regulating intestinal flora in Mycoplasma pneumoniae pneumonia mice

OBJECTIVE

Mycoplasma pneumoniae (MP) is a common pathogen that can cause respiratory infections. We explored the mechanisms of baicalin (BIA) affecting pulmonary inflammation and injury and regulated their intestinal flora through the TLR4/NF-κB pathway in MP pneumonia (MPP) mice with intestinal dysbiosis.

METHODS

The intestinal dysbiosis and the MPP mouse models with intestinal dysbiosis were established and treated with different doses of BIA, with lung wet-to-dry weight (W/D) ratio weighed. Kits were conducted to detect MP expression and serum C-reactive protein (CRP)/INF-γ/TNF-α/IL-1β/IL-8 levels, and RT-qPCR and Western blot to determine TLR4/MyD88/NF-κBp65 levels. Lung injury was assessed using HE staining, and intestinal flora structure using 16S rDNA sequencing. Gas chromatography-mass spectrometry determined fecal short-chain fatty acid (SFCA) content.

RESULTS

The broad-spectrum antibiotic mixture caused enlarged cecum, increased contents, darker color, weight loss, decreased intestinal flora abundance and diversity, and intestinal flora structure imbalance in mice. The MP-infected intestinal dysbiosis mice exhibited elevated MP expression, reduced body weight, increased W/D ratio, elevated serum CRP/INF-γ/TNFα/IL-1β/IL-8 levels, as well as interstitial pneumonitis in lungs. TLR4/MyD88/NF-κB p65 were elevated in lung tissues of MPP mice with intestinal dysbiosis. BIA partially reversed pulmonary inflammation and injury, and restored the flora diversity and SCFAs in MPP mice with intestinal dysbiosis.

CONCLUSION

BIA attenuated pulmonary inflammation and injury and modulated their intestinal flora imbalance by inhibiting the TLR4/NF-κB pathway in MPP mice with intestinal dysbiosis.

Health impacts of PM2.5 emissions from brake pad wear: A comprehensive study on pulmonary, metabolic, and microbiota alterations

The environmental impact of harmful particles from tire and brake systems is a growing concern. This study investigated the health impacts of PM2.5 emissions from brake pad wear on adult C57BL/6 mice. The mice were exposed to brake pad particles via intratracheal infusion, and various health parameters were assessed. The results showed that brake pad particle exposure significantly reduced lung function parameters such as tidal volume, peak expiratory time ratio, and peak inspiratory flow rate, while increasing the apnea index and airway stenosis index. Histological analysis revealed particle deposition, inflammatory damage, and potential fibrosis in the lungs. Additionally, inflammatory markers and fibrosis indicators were elevated in the lung tissue. Metabolomic analysis indicated changes in metabolites related to purine metabolism, protein digestion, nucleic acid metabolism, and pathways involving Caffeine, Xanthine, Inosine, and others. Gut microbiota analysis showed increased abundance of Odoribacter and Tuzzerella, and decreased abundance of Desulfovibrio and Butyricimonas. Correlation analysis further suggested a significant link between the abundance of Odoribacter and plasma metabolic changes. Overall, this study underscores the health risks associated with brake dust pollution, particularly its adverse effects on lung function and induction of lung damage and fibrosis.

The implication of microbiome in lungs cancer: mechanisms and strategies of cancer growth, diagnosis and therapy

Available evidence illustrates that microbiome is a promising target for the study of growth, diagnosis and therapy of various types of cancer. Lung cancer is a leading cause of cancer death worldwide. The relationship of microbiota and their products with diverse pathologic conditions has been getting large attention. The novel research suggests that the microbiome plays an important role in the growth and progression of lung cancer. The lung microbiome plays a crucial role in maintaining mucosal immunity and synchronizing the stability between tolerance and inflammation. Alteration in microbiome is identified as a critical player in the progression of lung cancer and negatively impacts the patient. Studies suggest that healthy microbiome is essential for effective therapy. Various clinical trials and research are focusing on enhancing the treatment efficacy by altering the microbiome. The regulation of microbiota will provide innovative and promising treatment strategies for the maintenance of host homeostasis and the prevention of lung cancer in lung cancer patients. In the current review article, we presented the latest progress about the involvement of microbiome in the growth and diagnosis of lung cancer. Furthermore, we also assessed the therapeutic status of the microbiome for the management and treatment of lung cancer.

The Future of Microbiome Therapeutics

The human microbiome exerts profound influence over various biological processes within the body. Unlike many host determinants, it represents a readily accessible target for manipulation to promote health benefits. However, existing commercial microbiome-directed products often exhibit low efficacy. Advancements in technology are paving the way for the development of novel microbiome therapeutics, across a wide range of indications. In this narrative review, we provide an overview of state-of-the-art technologies in late-stage development, examining their advantages and limitations. By covering a spectrum, from fecal-derived products to live biotherapeutics, phage therapy, and synthetic biology, we illuminate the path toward the future of microbiome therapeutics.

Unraveling the mechanisms underlying air pollution-induced dysfunction of the oral-gut-brain axis: implications for human health and well-being

Air pollution exposure has become an international health issue that poses many risks to life and health. The bidirectional regulatory network, known as the oral-gut-brain axis connects the oral cavity, intestine, and central nervous system, as well as its influence on health outcomes from exposure to air pollution is receiving increased attention. This article systematically details the epidemiological evidence linking air pollutants to diseases affecting the oral, respiratory, intestinal, and nervous systems, while also explaining the route of air pollutants via the oral-gut-brain axis. The oral-gut-brain axis anomalies resulting from air pollution and their underlying molecular processes are also covered. The study provides a fresh viewpoint on how exposure to air pollution affects health and investigates cutting-edge preventative and therapeutic techniques.