Links Between Inflammatory Bowel Disease and Chronic Obstructive Pulmonary Disease

Western diet promotes endometriotic lesion growth in mice and induces depletion of Akkermansia muciniphila in intestinal microbiota

BACKGROUND

Endometriosis, affecting 10% of women in their reproductive years, remains poorly understood. Both individual and environmental unexplained factors are implicated in this heterogenous condition. This study aims to examine the influence of a Western diet on endometriosis lesion development in mice and to uncover the mechanisms involved.

METHODS

Mice were fed either a control diet or a Western diet (high in fatty acids and low in fiber) for 4 weeks. Endometriosis was then surgically induced, and lesion development was monitored by ultrasound. After 7 weeks, the mice were sacrificed for analysis of lesion characteristics through RT-qPCR, immunohistochemistry, and flow cytometry. Additionally, the intestinal microbiota was assessed using 16S rRNA gene sequencing.

RESULTS

Mice on the Western diet developed lesions that were significantly twice as large compared to those on the control diet. These lesions exhibited greater fibrosis and proliferation, alongside enhanced macrophage activity and leptin pathway expression. Changes in the intestinal microbiota were significantly noted after endometriosis induction, regardless of diet. Notably, mice on the Western diet with the most substantial lesions showed a loss of Akkermansia Muciniphila in their intestinal microbiota.

CONCLUSIONS

A Western diet significantly exacerbates lesion size in a mouse model of endometriosis, accompanied by metabolic and immune alterations. The onset of endometriosis also leads to substantial shifts in intestinal microbiota, suggesting a potential link between diet, intestinal health, and endometriosis development.

Association of the gut microbiome and different phenotypes of COPD and asthma: a bidirectional Mendelian randomization study

Mounting evidence has revealed the association between gut microbiota and both chronic obstructive pulmonary disease (COPD) and asthma; however, the causal association between gut microbiota and specific disease phenotypes remains to be determined. This study employed bidirectional two-sample Mendelian randomization (MR) analyses to investigate the potential causal relationship between gut microbiota and these conditions. The research utilized genome-wide association study (GWAS) data from the MiBioGen consortium for gut microbiota and the integrative epidemiology unit (IEU) Open GWAS for these conditions. Four MR analysis methods were employed: the inverse variance weighted (IVW) test, MR-Egger, weighted median, and weighted mode methods. The IVW method results are considered the primary findings. Sensitivity analyses, including heterogeneity tests, horizontal pleiotropy analysis, and leave-one-out analysis, were used to enhance robustness. Our MR study identified eight gut microbiota taxa potentially associated with the risk of different types of COPD and asthma. These include two taxa for early-onset COPD: Streptococcaceae [odds ratio (OR) = 1.315, 95% confidence interval (CI) = 1.071-1.616, P = 0.009] and Holdemanella (OR = 1.199, 95% CI = 1.063-1.352, P = 0.003); three for later-onset COPD: Acidaminococcaceae (OR = 1.312, 95% CI = 1.098-1.567, P = 0.003), Holdemania (OR = 1.165, 95% CI = 1.039-1.305, P = 0.009), and Marvinbryantia (OR = 0.814, 95% CI = 0.697-0.951, P = 0.009); one for allergic asthma: Butyricimonas (OR = 0.794, 95% CI = 0.693-0.908, P = 0.001); and two for non-allergic asthma: Clostridia (OR = 1.255, 95% CI = 1.043-1.511, P = 0.016) and Clostridiales (OR = 1.256, 95% CI = 1.048-1.506, P = 0.014).IMPORTANCEIndividuals with diverse phenotypes of chronic obstructive pulmonary disease (COPD) and asthma exhibit different responses to the conventional "one treatment fits all" approach. Recent research has revealed the significant role of the gut-lung axis in both COPD and asthma. However, the specific impact of gut microbiota on different subtypes of these conditions remains poorly understood. Our study has identified eight gut microbiota that may be associated with the risk of different types of COPD and asthma. These findings provide evidence suggesting a potential causal relationship between gut microbiota and various phenotypes of COPD and asthma. This offers a new perspective on the origins of different disease phenotypes and points toward future exploration of phenotype-specific and personalized therapies.

Association Between Short-Term Exposure to Air Pollutants and Emergency Attendance for Upper Gastrointestinal Bleeding in Hong Kong: A Time-Series Study

The relationship between exposure to ambient air pollutants and emergency attendance for upper gastrointestinal bleeding (UGIB) remains inconclusive. This study examines the association between short-term exposure to various ambient pollutants and the risk of UGIB emergency attendance. Data on daily UGIB emergency attendance, ambient pollutants, and meteorological conditions in Hong Kong were collected from 2017 to 2022. A time-series study using a distributed lag non-linear model to analyze the data, considering lag days. Stratified analysis was performed based on sex, seasons, and the COVID-19 pandemic period. The burden was quantified using attributable fraction (AF) and number (AN). The study included 31,577 UGIB emergency records. Exposure to high levels of PM2.5 significantly increased the risk of UGIB emergency attendance from lag day 3 (RR: 1.012) to day 6 (RR: 1.008). High NO2 exposure also posed a significant risk from lag day 0 (RR: 1.026) to day 2 (RR: 1.014), and from lag day 5 (RR: 1.013) to day 7 (RR: 1.024). However, there was no association between UGIB and high O3 levels. The attributable burden of high-concentration NO2 exposure was higher compared to those of PM2.5. Males and elderly individuals (≥65 years) faced a higher risk of UGIB emergencies, particularly during cold seasons. Our study suggests that both PM2.5 and NO2 exposure are associated with an increased risk of emergency attendance for UGIB. Ambient pollutant exposure has a stronger effect on UGIB in males and the elderly, particularly during cold seasons.

Environmental and inflammatory factors influencing concurrent gut and lung inflammation

BACKGROUND

Crohn's disease and chronic obstructive pulmonary disease (COPD) are chronic inflammatory diseases that affect the gut and lung respectively and can occur comorbidly.

METHODS

Using the SHIP-1-/- model of Crohn's-like ileitis and chronic lung inflammation, the two diseases were co-investigated.

RESULTS

Contrary to prior literature, Crohn's-like ileitis was not fully penetrant in SHIP-1-/- mice, and housing in a specific pathogen-free facility was completely protective. Indeed, ileal tissue from SHIP-1-/- mice without overt ileitis was similar to control ilea. However, SHIP-1-/- mice with ileitis exhibited increased granulocytes in ileal tissue together with T cell lymphopenia and they lacked low abundance Bifidobacteria, suggesting this bacterium protects against ileitis. Lung disease, as defined by inflammation in lung washes, emphysema, and lung consolidation, was present in SHIP-1-/- mice regardless of ileitis phenotype; however, there was a shift in the nature of lung inflammation in animals with ileitis, with increased G-CSF and neutrophils, in addition to type 2 cytokines and eosinophils. Deficiency of G-CSF, which protects against lung disease, protected against the development of ileitis in SHIP-1-/- mice.

CONCLUSIONS

These studies have defined environmental, immune, and inflammatory factors that predispose to ileitis, and have identified that comorbid lung disease correlates with a granulocyte signature.

Air-Pollution-Mediated Microbial Dysbiosis in Health and Disease: Lung-Gut Axis and Beyond

Growing evidence suggests physiological and pathological functions of lung and gut microbiomes in various pathologies. Epidemiological and experimental data associate air pollution exposure with host microbial dysbiosis in the lungs and gut. Air pollution through increased reactive oxygen species generation, the disruption of epithelial barrier integrity, and systemic inflammation modulates microbial imbalance. Microbiome balance is crucial in regulating inflammation and metabolic pathways to maintain health. Microbiome dysbiosis is proposed as a potential mechanism for the air-pollution-induced modulation of pulmonary and systemic disorders. Microbiome-based therapeutic approaches are increasingly gaining attention and could have added value in promoting lung health. This review summarizes and discusses air-pollution-mediated microbiome alterations in the lungs and gut in humans and mice and elaborates on their role in health and disease. We discuss and summarize the current literature, highlight important mechanisms that lead to microbial dysbiosis, and elaborate on pathways that potentially link lung and lung microbiomes in the context of environmental exposures. Finally, we discuss the lung-liver-gut axis and its potential pathophysiological implications in air-pollution-mediated pathologies through microbial dysbiosis.

N4BP3 facilitates NOD2-MAPK/NF-κB pathway in inflammatory bowel disease through mediating K63-linked RIPK2 ubiquitination

The NOD2 signaling pathway, which plays an important role in the mechanisms of inflammatory bowel disease (IBD) development, has been closely associated with ubiquitination. It was revealed in this study that NOD2 receptor activation could obviously affect the expression of 19 ubiquitination-related genes, with N4BP3 being the most prominently expressed and upregulated. In addition, N4BP3 knockdown was found to reduce the mRNA levels of MDP-induced inflammatory factors, while N4BP3 overexpression elevated their mRNA levels as well as the levels of phospho-ERK1/2, phospho-JNK, phospho-P38 and phospho-NF-κB P65 proteins. Immunoprecipitation tests showed that N4BP3 could pull down RIPK2 and promote its K63-linked ubiquitination. In human tissue specimen assays and mouse experiments, we found that the expression of N4BP3 was significantly elevated in Crohn's disease (CD) patients and IBD mice, and N4BP3 knockdown reduced the dextran sulfate sodium-induced pathological score and the expression of inflammatory factors in the mouse colon tissue. In conclusion, N4BP3 is able to interact with RIPK2 and promote its K63-linked ubiquitination, to further promote the NOD2-MAPK/NF-κB pathway, thereby increasing promoting the release of inflammation factors and the degree of IBD inflammation.

The Influence of the Gut Microbiota on Host Health: A Focus on the Gut-Lung Axis and Therapeutic Approaches

The human gut microbiota is a complex ecosystem harboring thousands of microbial strains that play a crucial role in maintaining the overall well-being of its host. The composition of the gut microbiota varies with age from infancy to adulthood and is influenced by dietary habits, environment, and genetic disposition. Recent advances in culture-independent techniques and nucleic acid sequencing have improved our understanding of the diversity of the gut microbiota. The microbial species present in the gut release short-chain fatty acids (SCFAs), which have anti-inflammatory properties. The gut microbiota also plays a substantial role in modulating the host's immune system, promoting immune tolerance, and maintaining homeostasis. The impact of the gut microbiota on the health of the host is quite evident, as gut dysbiosis has been linked to various diseases, including metabolic disorders, autoimmune diseases, allergies, and inflammatory bowel diseases. The gut microbiota has bidirectional communication with the respiratory system, creating the gut-lung axis, which has been associated with different respiratory diseases. Therapeutic approaches targeting the gut microbiota, such as probiotics, prebiotics, dietary interventions, and fecal microbiota transplantation (FMT), aim to restore microbial balance and promote the growth of beneficial strains in the gut. Nonetheless, gaining knowledge of the complex interactions between the gut microbiota and the host is necessary to develop personalized medicine approaches and microbiota-based therapies for various conditions. This review summarizes studies related to the gut-lung axis with particular emphasis on the role of the microbiota. Future research directions are also discussed.

Increased Risk of Chronic Respiratory Disease among Individuals with Inflammatory Bowel Disease in a Prospective Cohort Study

BACKGROUND

Cross-sectional evidence suggests a higher burden of chronic respiratory diseases in people with inflammatory bowel disease, but there is a lack of prospective evidence to clarify the direction of their associations. We aimed to investigate the association of inflammatory bowel disease with the risk of 2 major chronic respiratory diseases, chronic obstructive pulmonary disease, and asthma.

METHODS

We included 430,414 participants from UK Biobank and followed them from recruitment (2006-2010) to 2021. Chronic obstructive pulmonary disease and asthma cases were obtained from inpatient data and death register. Using Cox proportional hazards models, we estimated the multivariable-adjusted hazard ratios (HR) of developing chronic obstructive pulmonary disease and asthma in participants with inflammatory bowel disease compared with inflammatory bowel disease-free groups. We also investigated the association among Crohn's disease and ulcerative colitis with the risk of chronic obstructive pulmonary disease and asthma.

RESULTS

Over a median follow-up of 11.9 years, there were 11,196 incidents of chronic obstructive pulmonary disease and 9831 asthma cases. The adjusted HRs of developing chronic obstructive pulmonary disease (HR 1.54; 95% confidence interval [CI], 1.33-1.79) and asthma (HR 1.52; 95% CI, 1.29-1.79) were higher for those with inflammatory bowel disease when compared with inflammatory bowel disease-free participants. Participants with Crohn's disease and ulcerative colitis were also found to have a higher risk of chronic obstructive pulmonary disease (Crohn's disease: HR 1.71; 95% CI, 1.36-2.15; ulcerative colitis: HR 1.45; 95% CI, 1.20-1.75) and asthma (Crohn's disease: HR 1.73; 95% CI, 1.33-2.25; ulcerative colitis: HR 1.41; 95% CI, 1.15-1.73) when compared with those free of inflammatory bowel disease.

CONCLUSIONS

This study suggested that individuals with inflammatory bowel disease have a higher risk of developing chronic obstructive pulmonary disease and asthma, highlighting the importance of preventing chronic respiratory diseases among inflammatory bowel disease patients.

Thirty-day outcomes of non-emergent colectomy for inflammatory bowel disease in patients with chronic obstructive pulmonary disease

BACKGROUND

Inflammatory bowel disease (IBD) can have significant colonic involvement and carries a long-term risk of surgical resection. Chronic obstructive pulmonary disease (COPD) and IBD share multiple inflammatory pathways, suggesting a bidirectional relationship through proposed pulmonary-intestinal cross-talk. This study aimed to examine the association between COPD and 30-day outcomes following non-emergent colectomies for IBD.

METHODS

Patients with IBD as the primary indication for colectomy were selected from National Surgical Quality Improvement Program (NSQIP) colectomy database 2012-2022. Emergency colectomy cases were excluded. A 1:3 propensity-score matching was used to balance the preoperative characteristics of COPD and non-COPD patients. Thirty-day postoperative outcomes were compared.

RESULTS

Among 25,285 patients who underwent colectomy for IBD, 365 (1.44 %) had COPD. Patients with COPD were older and had more comorbidities. After propensity-score matching, all COPD patients were matched to 1,095 patients without COPD. COPD and non-COPD patients had comparable 30-day mortality (3.29 % vs 2.19 %, p = 0.25). However, COPD patients had higher pulmonary complications (14.79 % vs 7.21 %, p < 0.01) attributed to pneumonia (10.14 % vs 4.02 %, p < 0.01), sepsis (12.88 % vs 8.68 %, p = 0.02), prolonged postoperative nothing by mouth (NPO) or nasogastric tube (NGT) use (28.22 % vs 22.10 %, p = 0.02), discharge not to home (40.28 % vs 34.02 %, p = 0.04), and longer length of stay (p = 0.01).

CONCLUSION

Therefore, given their mortality rates, colectomy is an effective treatment for IBD patients with concurrent COPD, while their postoperative care should include close monitoring of pulmonary symptoms and timely interventions to prevent further complications. Future research should explore the long-term prognosis of COPD patients after colectomy for IBD.

Pulmonary Manifestations of IBD: Case Report and Review of the Literature

This article explores the pulmonary complications associated with inflammatory bowel disease (IBD). It presents a detailed case study of a 22-year-old male with Crohn's disease exhibiting pulmonary symptoms. The review delves into the spectrum of pulmonary involvement in IBD, covering clinical presentations, diagnostic challenges, underlying pathophysiology, and management strategies. It highlights the significance of these extraintestinal manifestations on patient outcomes and quality of life. The article underscores the need for heightened clinical awareness and a systematic approach to diagnosis and management, integrating the expertise of multiple specialists. The review identifies gaps in current research, suggesting avenues for future investigation to enhance the understanding and treatment of these complex manifestations.

Effects of smoking on clinical treatment outcomes amongst patients with chronic inflammatory diseases initiating biologics: secondary analyses of the prospective BELIEVE cohort study

The prevalence and disease burden of chronic inflammatory diseases (CIDs) are predicted to rise. Patients are commonly treated with biological agents, but the individual treatment responses vary, warranting further research into optimizing treatment strategies. This study aimed to compare the clinical treatment responses in patients with CIDs initiating biologic therapy based on smoking status, a notorious risk factor in CIDs. In this multicentre cohort study including 233 patients with a diagnosis of Crohn's disease, ulcerative colitis, rheumatoid arthritis, axial spondyloarthritis, psoriatic arthritis or psoriasis initiating biologic therapy, we compared treatment response rates after 14 to 16 weeks and secondary outcomes between smokers and non-smokers. We evaluated the contrast between groups using logistic regression models: (i) a "crude" model, only adjusted for the CID type, and (ii) an adjusted model (including sex and age). Among the 205 patients eligible for this study, 53 (26%) were smokers. The treatment response rate among smokers (n = 23 [43%]) was lower compared to the non-smoking CID population (n = 92 [61%]), corresponding to a "crude" OR of 0.51 (95% CI: [0.26;1.01]) while adjusting for sex and age resulted in consistent findings: 0.51 [0.26;1.02]. The contrast was apparently most prominent among the 38 RA patients, with significantly lower treatment response rates for smokers in both the "crude" and adjusted models (adjusted OR 0.13, [0.02;0.81]). Despite a significant risk of residual confounding, patients with CIDs (rheumatoid arthritis in particular) should be informed that smoking probably lowers the odds of responding sufficiently to biological therapy. Registration: Clinical.Trials.gov NCT03173144.

A cross-sectional comparison of gut metagenomes between dairy workers and community controls

BACKGROUND

As a nexus of routine antibiotic use and zoonotic pathogen presence, the livestock farming environment is a potential hotspot for the emergence of zoonotic diseases and antibiotic resistant bacteria. Livestock can further facilitate disease transmission by serving as intermediary hosts for pathogens before a spillover event. In light of this, we aimed to characterize the microbiomes and resistomes of dairy workers, whose exposure to the livestock farming environment places them at risk for facilitating community transmission of antibiotic resistant genes and emerging zoonotic diseases.

RESULTS

Using shotgun sequencing, we investigated differences in the taxonomy, diversity and gene presence of 10 dairy farm workers and 6 community controls' gut metagenomes, contextualizing these samples with additional publicly available gut metagenomes. We found no significant differences in the prevalence of resistance genes, virulence factors, or taxonomic composition between the two groups. The lack of statistical significance may be attributed, in part, to the limited sample size of our study or the potential similarities in exposures between the dairy workers and community controls. We did, however, observe patterns warranting further investigation including greater abundance of tetracycline resistance genes and prevalence of cephamycin resistance genes as well as lower average gene diversity (even after accounting for differential sequencing depth) in dairy workers' metagenomes. We also found evidence of commensal organism association with tetracycline resistance genes in both groups (including Faecalibacterium prausnitzii, Ligilactobacillus animalis, and Simiaoa sunii).

CONCLUSIONS

This study highlights the utility of shotgun metagenomics in examining the microbiomes and resistomes of livestock workers, focusing on a cohort of dairy workers in the United States. While our study revealed no statistically significant differences between groups in taxonomy, diversity and gene presence, we observed patterns in antibiotic resistance gene abundance and prevalence that align with findings from previous studies of livestock workers in China and Europe. Our results lay the groundwork for future research involving larger cohorts of dairy and non-dairy workers to better understand the impact of occupational exposure to livestock farming on the microbiomes and resistomes of workers.

Outcomes and Hospital Service Use Among Patients With COPD in a Nurse- and Allied Health-Led Clinic

Importance

Multidisciplinary disease management efforts enable the improvement in lung function among patients with chronic obstructive pulmonary disease (COPD), but there is little evidence of its association with risks of adverse health outcomes and health care service use.

Objective

To examine the association between the use of a nurse- and allied health-led primary care clinic for respiratory patients, namely the Nurse and Allied Health Clinic-Respiratory Care (NAHC-Respiratory), and their risks of mortality and morbidity and health care service use.

Design, Setting, and Participants

This territory-wide, population-based, propensity-matched, retrospective cohort study used data from the electronic health records of all patients who used public health care services in Hong Kong, China, from January 1, 2010, to December 31, 2019. All patients with COPD treated in public outpatient clinics between January 1, 2010, and December 31, 2014, were included. Patients who attended NAHC-Respiratory and usual care only were propensity score-matched at a 1:2 ratio. Data analyses were conducted between August 2023 and April 2024.

Exposure

Attendance at NAHC-Respiratory.

Main Outcomes and Measures

All-cause and cause-specific mortality, incidence of COPD complications, and use of emergency department and inpatient services until the end of 2019 were compared between the NAHC-Respiratory and usual care participants using Cox proportional hazard regression, Poisson regression, and log-link gamma regression models after matching.

Results

This study included 9048 eligible patients after matching, including 3093 in the exposure group (2814 [91.0%] men; mean [SD] age, 69.8 [9.5] years) and 5955 in the reference group (5431 [91.2%] men; mean [SD] age, 69.5 [11.7] years). Compared with patients in the usual care-only group (reference), patients in the exposure group had lower risks of all-cause mortality (hazard ratio [HR], 0.84; 95% CI, 0.78-0.90) as well as pneumonia-caused (HR, 0.85; 95% CI, 0.74-0.97), respiratory-caused (HR, 0.86; 95% CI, 0.77-0.96), and cardiovascular-caused (HR, 0.74; 95% CI, 0.59-0.93) mortality. Exposure was associated with reduced rates of emergency department visits (incidence rate ratio [IRR], 0.92; 95% CI, 0.86-0.98) and hospitalization through emergency department (IRR, 0.89; 95% CI, 0.83-0.95).

Conclusions

In this cohort study, the use of a nurse- and allied health-led clinic in primary care settings was associated with reduced risks of mortality and use of hospital services among patients with COPD. These findings emphasize the important role of health care workers other than physicians in disease management in the primary care setting. The NAHC-Respiratory model and service components can be used to help improve primary care programs to benefit more patients with COPD.

The role of gut-lung axis in COPD: Pathogenesis, immune response, and prospective treatment

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and healthcare burden worldwide. The progression of COPD is a combination of genetic predisposition and environmental factors, primarily cigarette smoking, and the underlying mechanisms are still unknown. Intestinal microecology impacts host immunity, metabolism, and resistance to pathogenic infections, which may be involved in pulmonary disease. Moreover, substantial interaction occurs between the intestinal and respiratory immune niches. After reviewing nearly 500 articles, we found the gut-lung axis plays an important role in the development of COPD. COPD patients often have dysbiosis of the intestinal microenvironment, which can affect host immunity through a series of mechanisms, exacerbating or protecting against COPD progression. This paper summarizes how the gut-lung axis influences COPD, including the alterations of intestinal microecology, the pathological mechanisms, and the involved immune responses. Finally, we summarize the latest research advances in COPD treatment from the perspective of regulating the gut-lung axis and intestinal immunity and evaluate the potential value of the gut-lung axis in improving COPD prognosis.

Risk Factors of Pneumocystis jirovecii Pneumonia in Patients with Inflammatory Bowel Disease: A Nationwide Population-Based Study

Background/Aims

: Pneumocystis jirovecii pneumonia (PJP) is a rare but potentially fatal infection. This study was conducted to investigate the risk factors for PJP in inflammatory bowel disease (IBD) patients.

Methods

: This nationwide, population-based study was conducted in Korea using claims data. Cases of PJP were identified in patients diagnosed with ulcerative colitis (UC) or Crohn's disease (CD) between 2010 and 2017, and the clinical data of each patient was analyzed. Dual and triple therapy was defined as the simultaneous prescription of two or three of the following drugs: steroids, calcineurin inhibitors, immunomodulators, and biologics.

Results

: During the mean follow-up period (4.6±2.3 years), 84 cases of PJP were identified in 39,462 IBD patients (31 CD and 53 UC). For CD patients, only age at diagnosis >40 years (hazard ratio [HR], 6.12; 95% confidence interval [CI], 1.58 to 23.80) was significantly associated with the risk of PJP, whereas in UC patients, diagnoses of diabetes (HR, 2.51; 95% CI, 1.19 to 5.31) and chronic obstructive pulmonary disease (HR, 3.41; 95% CI, 1.78 to 6.52) showed significant associations with PJP risk. Triple therapy increased PJP risk in both UC (HR, 3.90; 95% CI, 1.54 to 9.88) and CD patients (HR, 5.69; 95% CI, 2.32 to 14.48). However, dual therapy increased PJP risk only in UC patients (HR, 2.53; 95% CI, 1.36 to 4.70). Additionally, 23 patients (27%) received intensive care treatment, and 10 (12%) died within 30 days.

Conclusions

: PJP risk factors differ in CD and UC patients. Considering the potential fatality of PJP, prophylaxis should be considered for at-risk IBD patients.

Increased risk of obstructive lung disease in inflammatory bowel disease: A population-based cohort study

BACKGROUND AND AIMS

Inflammatory bowel disease (IBD) is associated with disease manifestations in organs other than the gastrointestinal tract. In this study, we aimed to estimate the odds of obstructive lung disease (OLD) before IBD onset and the risk of OLD after IBD onset.

METHODS

In a nationwide population-based Danish cohort study from 1999 to 2018, individuals with IBD and OLD were identified using the Danish registries. Between 2003 and 2013, 24,238 individuals with IBD were identified and matched 1:10 with non-IBD individuals. Logistic regression was used to estimate the prevalence odds ratio for OLD before IBD onset. Time-to-event analysis was performed to explore the risk of OLD after IBD onset. In a sensitivity analysis, the time-to-event analysis was repeated using the composite outcome OLD and the separate outcomes, chronic obstructive pulmonary disease (COPD), asthma, and bronchiectasis.

RESULTS

Individuals with IBD were 60% more likely to have OLD before onset (adjusted odds ratio: 1.60, 95% confidence interval [CI]: 1.53-1.67). Furthermore, their risk of OLD was more than 40% higher after IBD diagnosis (adjusted hazard ratio [aHR]: 1.43, 95% CI: 1.37-1.49). The sensitivity analysis increased the risk to 60% (aHR: 1.63, 95% CI: 1.53-1.73). Similar results were found for COPD and asthma separately, whereas the risk of bronchiectasis increased more than 2-fold (aHR: 2.44, 95% CI: 1.91-3.11).

CONCLUSION

The odds of OLD before- and the risk following an IBD diagnosis were increased. We encourage physicians to be vigilant of pulmonary symptoms in persons with IBD and gastrointestinal symptoms in individuals with OLD.

Bufei Huoxue capsule attenuates COPD-related inflammation and regulates intestinal microflora, metabolites

Background: Bufei Huoxue capsule (BFHX) is widely used for the clinical treatment of chronic obstructive pulmonary disease (COPD) in China. Objectives: The aim of this study is to explore the effects on COPD and the underlying mechanism of BFHX. The process and methods: In this study, we established a COPD mouse model through cigarette smoke (CS) exposure in combination with lipopolysaccharide (LPS) intratracheal instillation. Subsequently, BFHX was orally administrated to COPD mice, and their pulmonary function, lung pathology, and lung inflammation, including bronchoalveolar lavage fluid (BALF) cell count and classification and cytokines, were analyzed. In addition, the anti-oxidative stress ability of BFHX was detected by Western blotting, and the bacterial diversity, abundance, and fecal microbiome were examined using 16S rRNA sequencing technology. Outcome: BFHX was shown to improve pulmonary function, suppress lung inflammation, decrease emphysema, and increase anti-oxidative stress, whereas 16S rRNA sequencing indicated that BFHX can dynamically regulate the diversity, composition, and distribution of the intestinal flora microbiome and regulate the lysine degradation and phenylalanine metabolism of COPD mice. These results highlight another treatment option for COPD and provide insights into the mechanism of BFHX.

Gut Microbiome and Transcriptomic Changes in Cigarette Smoke-Exposed Mice Compared to COPD and CD Patient Datasets

Chronic obstructive pulmonary disease (COPD) patients and smokers have a higher incidence of intestinal disorders. The aim of this study was to gain insight into the transcriptomic changes in the lungs and intestines, and the fecal microbial composition after cigarette smoke exposure. Mice were exposed to cigarette smoke and their lung and ileum tissues were analyzed by RNA sequencing. The top 15 differentially expressed genes were investigated in publicly available gene expression datasets of COPD and Crohn's disease (CD) patients. The murine microbiota composition was determined by 16S rRNA sequencing. Increased expression of MMP12, GPNMB, CTSK, CD68, SPP1, CCL22, and ITGAX was found in the lungs of cigarette smoke-exposed mice and COPD patients. Changes in the intestinal expression of CD79B, PAX5, and FCRLA were observed in the ileum of cigarette smoke-exposed mice and CD patients. Furthermore, inflammatory cytokine profiles and adhesion molecules in both the lungs and intestines of cigarette smoke-exposed mice were profoundly changed. An altered intestinal microbiota composition and a reduction in bacterial diversity was observed in cigarette smoke-exposed mice. Altered gene expression in the murine lung was detected after cigarette smoke exposure, which might simulate COPD-like alterations. The transcriptomic changes in the intestine of cigarette smoke-exposed mice had some similarities with those of CD patients and were associated with changes in the intestinal microbiome. Future research could benefit from investigating the specific mechanisms underlying the observed gene expression changes due to cigarette smoke exposure, focusing on identifying potential therapeutic targets for COPD and CD.

Antibiotic administration aggravates asthma by disrupting gut microbiota and the intestinal mucosal barrier in an asthma mouse model

In humans, gut microbiota can determine the health status. The regulatory mechanisms of the gut microbiota in asthma must be elucidated. Although antibiotics (ABXs) can clear infections, they markedly alter the composition and abundance of gut microbiota. The present study used ABX-treated mice to examine the time-dependent effects of ABX administration on the gut microbiota and intestinal mucosal barrier. The mouse asthma model was established using ovalbumin (OVA) and gavaged with an ABX cocktail for different durations (1 or 2 weeks) and stacked sequences. The pathology of the model, model 2, OVA-ABX, OVA-ABX 2, ABX-OVA and ABX-OVA was severe when compared with the control group as evidenced by the following results: i) significantly increased pulmonary and colonic inflammatory cell infiltration; ii) enhanced pause values and iii) OVA-induced immunoglobulin E (IgE) and TGF-β expression levels, and significantly downregulated Tight Junction Protein 1 (TJP1), claudin 1 and Occludin expression levels. Furthermore, the intestinal bacterial load in the OVA-ABX and OVA-ABX 2 groups was significantly lower than that in the ABX-OVA and ABX-OVA 2 groups, respectively. The predominant taxa were as follows: phyla, Firmicutes and Proteobacteria, genera, Escherichia-Shigella, Lactobacillus and Lachnospira. The abundances of Lachnospira and Escherichia-Shigella were correlated with the expression of OVA-induced IgE and TJPs. These findings indicated that ABX administration, which modifies microbiome diversity and bacterial abundance, can disrupt colonic integrity, downregulate TJ proteins, damage the intestinal barrier, enhance enterocyte permeability, and promote the release of inflammatory factors, adversely affecting asthma alleviation and long-term repair.

Probiotics combined with Budesonide and Ipratropium bromide for chronic obstructive pulmonary disease: A retrospective analysis

To explore the effect of probiotics combined with budesonide and ipratropium bromide in the treatment of chronic obstructive pulmonary disease (COPD) on lung function and gut microbiota. This was a retrospective study of prospectively collected clinical data of 118 patients with COPD admitted to our hospital between January 2020 and December 2022. According to the treatment records, 59 patients received budesonide and irpratropium bromide (control group), and 59 patients received probiotics combined with budesonide and irpratropium bromide (observation group). The lung function, inflammatory factor levels, airway remodeling, and gut microbiota before and after treatment were compared between the 2 groups. After treatment, FVC, MMEF, PEF, and FEV1 in the 2 groups were higher than before treatment, and the values in the observation group were higher than those in the control group (P < .05). After treatment, the serum levels of TNF-α, IL-6, and PCT in the 2 groups were lower than before treatment, and the levels in the observation group were lower than those in the control group (P < .05). After treatment, the levels of serum MMP-9, VEGF, basic fibroblast growth factor, and NGF in the 2 groups were lower than before treatment, and the levels in the observation group were lower than those in the control group (P < .05). After treatment, the levels of lactobacilli and bifidobacteria in the 2 groups increased compared to those before treatment, and the observation group had a higher level, while the levels of Enterobacteriaceae and Enterococcus were lower in the observation group than those before treatment (P < .05). Based on budesonide and irpratropium bromide, probiotic treatment of COPD is more conducive to reducing the degree of inflammatory reactions, inhibiting airway remodeling, regulating the level of gut microbiota, and promoting the recovery of lung function.

The association between chronic obstructive pulmonary disease and autoimmune diseases: a bidirectional Mendelian randomization study

Objective

Observational studies have reported that chronic obstructive pulmonary disease (COPD) is often accompanied by autoimmune diseases, but the causal relationships between them remain uncertain. In this Mendelian study, we aimed to investigate the potential causal relationship between COPD and four common autoimmune diseases.

Methods

We conducted an analysis of summary data on COPD and autoimmune disease using publicly available genome-wide association studies (GWAS) summary data. We initially employed the inverse- variance weighted method as the primary approach to establish the causal impact of COPD on autoimmune diseases in the sample and conducted additional sensitivity analyses to examine the robustness of the results. Subsequently, we performed reverse Mendelian randomization (MR) analyses for the four autoimmune diseases. Finally, the potential for bidirectional causal relationships was assessed.

Results

Our MR analysis revealed no significant causal relationship between COPD and any of the studied autoimmune diseases. However, reverse MR results indicated a significant association between rheumatoid arthritis (RA), osteoarthritis (OA) and the risk of developing COPD, with respective odds ratios (OR) of 377.313 (95% CI, 6.625-21487.932, P = 0.004) for RA and 11.097 (95% CI, 1.583-77.796, P = 0.015) for OA. Sensitivity analyses confirmed the robustness of the results.

Conclusion

Our findings support a potential causal relationship between autoimmune diseases and COPD, highlighting the importance of considering comorbidities in clinical management of COPD.

Exploring the Interplay between COVID-19 and Gut Health: The Potential Role of Prebiotics and Probiotics in Immune Support

The COVID-19 pandemic has profoundly impacted global health, leading to extensive research focused on developing strategies to enhance outbreak response and mitigate the disease's severity. In the aftermath of the pandemic, attention has shifted towards understanding and addressing long-term health implications, particularly in individuals experiencing persistent symptoms, known as long COVID. Research into potential interventions to alleviate long COVID symptoms has intensified, with a focus on strategies to support immune function and mitigate inflammation. One area of interest is the gut microbiota, which plays a crucial role in regulating immune responses and maintaining overall health. Prebiotics and probiotics, known for their ability to modulate the gut microbiota, have emerged as potential therapeutic agents in bolstering immune function and reducing inflammation. This review delves into the intricate relationship between long COVID, the gut microbiota, and immune function, with a specific focus on the role of prebiotics and probiotics. We examine the immune response to long COVID, emphasizing the importance of inflammation and immune regulation in the persistence of symptoms. The potential of probiotics in modulating immune responses, including their mechanisms in combating viral infections such as COVID-19, is discussed in detail. Clinical evidence supporting the use of probiotics in managing long COVID symptoms is summarized, highlighting their role as adjunctive therapy in addressing various aspects of SARS-CoV-2 infection and its aftermath.

What Makes the Gut-Lung Axis Working? From the Perspective of Microbiota and Traditional Chinese Medicine

Background

An increasing number of studies have proved that gut microbiota is involved in the occurrence and development of various lung diseases and can interact with the diseased lung. The concept of the gut-lung axis (GLA) provides a new idea for the subsequent clinical treatment of lung diseases through human microbiota. This review aims to summarize the microbiota in the lung and gut and the interaction between them from the perspectives of traditional Chinese medicine and modern medicine.

Method

We conducted a literature search by using the search terms "GLA," "gut microbiota," "spleen," and "Chinese medicine" in the databases PubMed, Web of Science, and CNKI. We then explored the mechanism of action of the gut-lung axis from traditional Chinese medicine and modern medicine.

Results

The lung and gut microbiota enable the GLA to function through immune regulation, while metabolites of the gut microbiota also play an important role. The spleen can improve the gut microbiota to achieve the regulation of the GLA.

Conclusion

Improving the gut microbiota through qi supplementation and spleen fortification provides a new approach to the clinical treatment of lung diseases by regulating the GLA. Currently, our understanding of the GLA is limited, and more research is needed to explain its working principle.

Unraveling the gut-Lung axis: Exploring complex mechanisms in disease interplay

The link between gut and lung starts as early as during organogenesis. Even though they are anatomically distinct, essential bidirectional crosstalk via complex mechanisms supports GLA. Emerging studies have demonstrated the association of gut and lung diseases via multifaceted mechanisms. Advancements in omics and metagenomics technologies revealed a potential link between gut and lung microbiota, adding further complexity to GLA. Despite substantial studies on GLA in various disease models, mechanisms beyond microbial dysbiosis regulating the interplay between gut and lung tissues during disease conditions are not thoroughly reviewed. This review outlines disease specific GLA mechanisms, emphasizing research gaps with a focus on gut-to-lung direction based on current GLA literature. Moreover, the review discusses potential gut microbiota and their products like metabolites, immune modulators, and non-bacterial contributions as a basis for developing treatment strategies for lung diseases. Advanced experimental methods, modern diagnostic tools, and technological advancements are also highlighted as crucial areas for improvement in developing novel therapeutic approaches for GLA-related diseases. In conclusion, this review underscores the importance of exploring additional mechanisms within the GLA to gain a deeper understanding that could aid in preventing and treating a wide spectrum of lung diseases.

Edible pueraria lobata-derived exosome-like nanovesicles ameliorate dextran sulfate sodium-induced colitis associated lung inflammation through modulating macrophage polarization

BACKGROUND

Inflammatory bowel diseases (IBD), such as severe colitis, are associated with the development of lung inflammation and tissue damage. Pueraria lobata (P. lobata) plays an essential role in controlling cytokines. However, the exact mechanism of the inflammation response is still unknown.

PURPOSE

To investigate the effects of the P. lobata-derived exosomes-like nanovesicles (PLDENs) on colitis and their role in the lung inflammatory response.

METHODS

In this study, we investigated the effects of PLDENs on the dextran sulfate sodium (DSS)-induced colitis and explored the mechanisms by forming the gut-lung axis. PLDENs were characterized by mass spectrometry-based proteomic analysis.

RESULTS

The results showed that PLDENs had significant preventive effects in DSS-induced colitis and pathological changes in colons in a dose-dependent manner. Simultaneously, the treatment of PLDENs could effectively reduce inflammatory changes in the lung. PLDENs could selectively regulate the composition of gut microbiota.

CONCLUSION

These data suggested that the treatment of PLDENs could 'attenuate DSS-induced colitis and lung inflammation, providing an efficacious supplement for reducing co-morbidities in IBD patients.

Multiomics was used to clarify the mechanism by which air pollutants affect chronic obstructive pulmonary disease: A human cohort study

Exposure to air pollutants has been associated with various adverse health outcomes, including chronic obstructive pulmonary disease (COPD). However, the precise underlying mechanism by which air pollution impacts COPD through remains insufficiently understood. To elucidated the molecular mechanism by which air pollutant exposure contributes to alterations in the gut microbiome and metabolism in AECOPD patients, we employed metagenomics and untargeted metabolomics to analyse the gut microbial, faecal, and serum metabolites. The correlations among air pollutants, gut microbes, serum metabolites, and blood biochemical markers were assessed using generalised additive mixed models and Spearman correlation analysis. The findings revealed that for every 10 μg/m3 increase in PM2.5 concentration, the α-diversity of the gut flora decreased by 2.16% (95% CI: 1.80%-2.53%). We found seven microorganisms that were significantly associated with air pollutants, of which Enterococcus faecium, Bacteroides fragilis, Ruthenibacterium lactatiformans, and Subdoligranulum sp.4_3_54A2FAA were primarily associated with glycolysis. We identified 13 serum metabolites and 17 faecal metabolites significantly linked to air pollutants. Seven of these metabolites, which were strongly associated with air pollutants and blood biochemical indices, were found in both serum and faecal samples. Some of these metabolites, such as 2,5-furandicarboxylic acid, C-8C1P and melatonin, were closely associated with disturbances in lipid and fatty acid metabolism in AECOPD patients. These findings underscore the impact of air pollutants on overall metabolism based on influencing gut microbes and metabolites in AECOPD patients. Moreover, these altered biomarkers establish the biologic connection between air pollutant exposure and AECOPD outcomes.The identification of pertinent biomarkers provides valuable insights for the development of precision COPD prevention strategies.

Predicting mixed venous oxygen saturation (SvO2) impairment in COPD patients using clinical-CT radiomics data: A preliminary study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is one of the most common chronic airway diseases in the world.

OBJECTIVE

To predict the degree of mixed venous oxygen saturation (SvO2) impairment in patients with COPD by modeling using clinical-CT radiomics data and to provide reference for clinical decision-making.

METHODS

A total of 236 patients with COPD diagnosed by CT and clinical data at Xiangyang No. 1 People's Hospital (n= 157) and Xiangyang Central Hospital (n= 79) from June 2018 to September 2021 were retrospectively analyzed. The patients were divided into group A (SvO⩾2 62%, N= 107) and group B (SvO<2 62%, N= 129). We set up training set and test set at a ratio of 7/3 and time cutoff spot; In training set, Logistic regression was conducted to analyze the differences in general data (e.g. height, weight, systolic blood pressure), laboratory indicators (e.g. arterial oxygen saturation and pulmonary artery systolic pressure), and CT radiomics (radscore generated using chest CT texture parameters from 3D slicer software and LASSO regression) between these two groups. Further the risk factors screened by the above method were used to establish models for predicting the degree of hypoxia in COPD, conduct verification in test set and create a nomogram.

RESULTS

Univariate analysis demonstrated that age, smoking history, drinking history, systemic systolic pressure, digestive symptoms, right ventricular diameter (RV), mean systolic pulmonary artery pressure (sPAP), cardiac index (CI), pulmonary vascular resistance (PVR), 6-min walking distance (6MWD), WHO functional classification of pulmonary hypertension (WHOPHFC), the ratio of forced expiratory volume in the first second to the forced vital capacity (FEV1%), and radscore in group B were all significantly different from those in group A (P< 0.05). Multivariate regression demonstrated that age, smoking history, digestive symptoms, 6MWD, and radscore were independent risk factors for SvO2 impairment. The combined model established based on the abovementioned indicators exhibited a good prediction effect [AUC: 0.903; 95%CI (0.858-0.937)], higher than the general clinical model [AUC: 0.760; 95%CI (0.701-0.813), P< 0.05] and laboratory examination-radiomics model [AUC: 0.868; 95%CI (0.818-0.908), P= 0.012]. The newly created nomogram may be helpful for clinical decision-making and benefit COPD patients.

CONCLUSION

SvO2 is an important indicator of hypoxia in COPD, and it is highly related to age, 6MWD, and radscore. The combined model is helpful for early identification of SvO2 impairment and adjustment of COPD treatment strategies.

Potential systemic effects of acquired CFTR dysfunction in COPD

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation, respiratory symptoms, inflammation of the airways, and systemic manifestations of the disease. Genetic susceptibility and environmental factors are important in the development of the disease, particularly exposure to cigarette smoke which is the most notable risk factor. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are the cause of cystic fibrosis (CF), which shares several pathophysiological pulmonary features with COPD, including airway obstruction, chronic airway inflammation and bacterial colonization; in addition, both diseases also present systemic defects leading to comorbidities such as pancreatic, gastrointestinal, and bone-related diseases. In patients with COPD, systemic CFTR dysfunction can be acquired by cigarette smoking, inflammation, and infection. This dysfunction is, on average, about half of that found in CF. Herein we review the literature focusing on acquired CFTR dysfunction and the potential role in the pathogenesis of comorbidities associated with COPD and chronic bronchitis.

The re-emerging role of linoleic acid in paediatric asthma

Asthma is the most common chronic disease within the paediatric population. Although it is multifactorial, its onset may be linked to early-life exposures with subsequent impact on immune system development. Microbial and dietary metabolic products have been implicated in the development and exacerbation of paediatric asthma. Linoleic acid is the most common omega-6 polyunsaturated fatty acid in the Western diet. In this review, we summarise the literature regarding the involvement of linoleic acid in the development of and its impact on existing paediatric asthma. First, we summarise the existing knowledge surrounding the relationship between human microbial metabolism and allergic diseases in children. Next, we examine cellular or animal model-based mechanistic studies that investigated the impact of dietary- and microbial-derived linoleic acid metabolites on asthma. Finally, we review the literature investigating the impact of linoleic acid metabolites on the development and exacerbation of childhood asthma. While there is conflicting evidence, there is growing support for a role of linoleic acid in the onset and pathophysiology of asthma. We recommend that additional cellular, animal, and longitudinal studies are performed that target linoleic acid and its metabolites.

Nicotinic acetylcholine receptor signaling maintains epithelial barrier integrity

Disruption of epithelial barriers is a common disease manifestation in chronic degenerative diseases of the airways, lung, and intestine. Extensive human genetic studies have identified risk loci in such diseases, including in chronic obstructive pulmonary disease (COPD) and inflammatory bowel diseases. The genes associated with these loci have not fully been determined, and functional characterization of such genes requires extensive studies in model organisms. Here, we report the results of a screen in Drosophila melanogaster that allowed for rapid identification, validation, and prioritization of COPD risk genes that were selected based on risk loci identified in human genome-wide association studies (GWAS). Using intestinal barrier dysfunction in flies as a readout, our results validate the impact of candidate gene perturbations on epithelial barrier function in 56% of the cases, resulting in a prioritized target gene list. We further report the functional characterization in flies of one family of these genes, encoding for nicotinic acetylcholine receptor (nAchR) subunits. We find that nAchR signaling in enterocytes of the fly gut promotes epithelial barrier function and epithelial homeostasis by regulating the production of the peritrophic matrix. Our findings identify COPD-associated genes critical for epithelial barrier maintenance, and provide insight into the role of epithelial nAchR signaling for homeostasis.

Polydatin alleviates bleomycin-induced pulmonary fibrosis and alters the gut microbiota in a mouse model

To investigate the effect and mechanism of polydatin on bleomycin (BLM)-induced pulmonary fibrosis in a mouse model. The lung fibrosis model was induced by BLM. The contents of TNF-α, LPS, IL-6 and IL-1β in lung tissue, intestine and serum were detected by ELISA. Gut microbiota diversity was detected by 16S rDNA sequencing; R language was used to analyse species composition, α-diversity, β-diversity, species differences and marker species. Mice were fed drinking water mixed with four antibiotics (ampicillin, neomycin, metronidazole, vancomycin; antibiotics, ABx) to build a mouse model of ABx-induced bacterial depletion; and faecal microbiota from different groups were transplanted into BLM-treated or untreated ABx mice. The histopathological changes and collagen I and α-SMA expression were determined. Polydatin effectively reduced the degree of fibrosis in a BLM-induced pulmonary fibrosis mouse model; BLM and/or polydatin affected the abundance of the dominant gut microbiota in mice. Moreover, faecal microbiota transplantation (FMT) from polydatin-treated BLM mice effectively alleviated lung fibrosis in BLM-treated ABx mice compared with FMT from BLM mice. Polydatin can reduce fibrosis and inflammation in a BLM-induced mouse pulmonary fibrosis model. The alteration of gut microbiota by polydatin may be involved in the therapeutic effect.

Advances in metabolomics of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a chronic lung disease with limited airflow. COPD is characterized by chronic bronchitis and emphysema, and is often accompanied by malnutrition with fatigue, muscle weakness, and an increased risk of infection. Although the pulmonary function test is used as the gold criterion for diagnosing COPD, it is unable to identify early COPD or classify the subtypes, thereby impeding early intervention and the precise diagnosis of COPD. Recent evidence suggests that metabolic dysfunction, such as changes in lipids, amino acids, glucose, nucleotides, and microbial metabolites in the lungs and intestine, have a great potential for diagnosing COPD in the early stage. However, a comprehensive summary of these metabolites and their effects on COPD is still lacking. This review summarizes the metabolites that are changed in COPD and highlights some promising early diagnostic markers and therapeutic targets. We emphasize that intensified dietary management may be among the most feasible methods to improve metabolism in the body.

Lactobacillus rhamnosus Modulates Lung Inflammation and Mitigates Gut Dysbiosis in a Murine Model of Asthma-COPD Overlap Syndrome

The asthma-COPD overlap syndrome (ACOS) presents lung inflammation similar to both asthma and chronic obstructive pulmonary disease (COPD). Due to the immune response between the lung and gut, it is possible that ACOS individuals present gut dysbiosis. Due to therapeutic limitations in ACOS, Lactobacillus rhamnosus (Lr) have received attention once Lr has been effective in asthma and COPD. However, there is no data about the Lr effect on both lung inflammation and gut dysbiosis in ACOS. Thus, our study investigated the Lr effect on lung inflammation, bronchoconstriction, airway remodeling, and gut dysbiosis in the murine ACOS model. Treated mice with Lr were exposed to HDM and cigarette smoke to induce ACOS. Sixty days after ACOS induction, mice were euthanized. Lung inflammation was evaluated in leukocytes in bronchoalveolar lavage fluid (BALF), airway remodeling, cytokine secretion, and transcription factor expression in the lung. The gut microbiota was assayed by 16S mRNA sequencing from a fecal sample. Leukocyte population, bronchial hyperreactivity, pro-inflammatory cytokines, and airway remodeling were attenuated in Lr-treated ACOS mice. Likewise, IL-4, IL-5, and IL-13, STAT6 and GATA3, as well as IL-17, IL-21, IL-22, STAT3, and RORɣt were reduced after Lr. In addition, IL-2, IL-12, IFN-γ, STAT1, and T-bet as well as IL-10, TGF-β, STAT5, and Foxp3 were restored after the Lr. Firmicutes was reduced, while Deferribacteres was increased after Lr. Likewise, Lr decreased Staphylococcus and increased Mucispirillum in ACOS mice. Lr improves fecal bacterial β-diversity. Our findings show for the first time the Lr effect on lung inflammation and gut dysbiosis in murine ACOS.

Lung Involvement in Inflammatory Bowel Diseases: Shared Pathways and Unwanted Connections

Inflammatory bowel diseases (IBDs) are chronic, relapsing inflammatory disorders of the gastrointestinal tract, frequently associated with extraintestinal manifestations (EIMs) that can severely affect IBD patients' quality of life, sometimes even becoming life-threatening. Respiratory diseases have always been considered a rare and subsequently neglected extraintestinal manifestations of IBD. However, increasing evidence has demonstrated that respiratory involvement is frequent in IBD patients, even in the absence of respiratory symptoms. Airway inflammation is the most common milieu of IBD-related involvement, with bronchiectasis being the most common manifestation. Furthermore, significant differences in prevalence and types of involvement are present between Crohn's disease and ulcerative colitis. The same embryological origin of respiratory and gastrointestinal tissue, in addition to exposure to common antigens and cytokine networks, may all play a potential role in the respiratory involvement. Furthermore, other causes such as drug-related toxicity and infections must always be considered. This article aims at reviewing the current evidence on the association between IBD and respiratory diseases. The purpose is to raise awareness of respiratory manifestation among IBD specialists and emphasize the need for identifying respiratory diseases in early stages to promptly treat these conditions, avoid worsening morbidity, and prevent lung damage.

Research progress on the effects of gut microbiome on lung damage induced by particulate matter exposure

Air pollution is one of the top five causes of death in the world and has become a research hotspot. In the past, the health effects of particulate matter (PM), the main component of air pollutants, were mainly focused on the respiratory and cardiovascular systems. However, in recent years, the intestinal damage caused by PM and its relationship with gut microbiome (GM) homeostasis, thereby affecting the composition and function of GM and bringing disease burden to the host lung through different mechanisms, have attracted more and more attention. Therefore, this paper reviews the latest research progress in the effect of PM on GM-induced lung damage and its possible interaction pathways and explores the potential immune inflammatory mechanism with the gut-lung axis as the hub in order to understand the current research situation and existing problems, and to provide new ideas for further research on the relationship between PM pollution, GM, and lung damage.

Mechanisms of Lung and Intestinal Microbiota and Innate Immune Changes Caused by Pathogenic Enterococcus Faecalis Promoting the Development of Pediatric Pneumonia

Bacterial pneumonia is the main cause of illness and death in children under 5 years old. We isolated and cultured pathogenic bacteria LE from the intestines of children with pneumonia and replicated the pediatric pneumonia model using an oral gavage bacterial animal model. Interestingly, based on 16srRNA sequencing, we found that the gut and lung microbiota showed the same imbalance trend, which weakened the natural resistance of this area. Further exploration of its mechanism revealed that the disruption of the intestinal mechanical barrier led to the activation of inflammatory factors IL-6 and IL-17, which promoted the recruitment of ILC-3 and the release of IL-17 and IL-22, leading to lung inflammation. The focus of this study is on the premise that the gut and lung microbiota exhibit similar destructive changes, mediating the innate immune response to promote the occurrence of pneumonia and providing a basis for the development and treatment of new drugs for pediatric pneumonia.

The lung-gut crosstalk in respiratory and inflammatory bowel disease

Both lung and gut belong to the common mucosal immune system (CMIS), with huge surface areas exposed to the external environment. They are the main defense organs against the invasion of pathogens and play a key role in innate and adaptive immunity. Recently, more and more evidence showed that stimulation of one organ can affect the other, as exemplified by intestinal complications during respiratory disease and vice versa, which is called lung-gut crosstalk. Intestinal microbiota plays an important role in respiratory and intestinal diseases. It is known that intestinal microbial imbalance is related to inflammatory bowel disease (IBD), this imbalance could impact the integrity of the intestinal epithelial barrier and leads to the persistence of inflammation, however, gut microbial disturbances have also been observed in respiratory diseases such as asthma, allergy, chronic obstructive pulmonary disease (COPD), and respiratory infection. It is not fully clarified how these disorders happened. In this review, we summarized the latest examples and possible mechanisms of lung-gut crosstalk in respiratory disease and IBD and discussed the strategy of shaping intestinal flora to treat respiratory diseases.

Impact of the gut-lung axis on tuberculosis susceptibility and progression

Tuberculosis (TB) has remained at the forefront of the global infectious disease burden for centuries. Concerted global efforts to eliminate TB have been hindered by the complexity of Mycobacterium tuberculosis (Mtb), the emergence of antibiotic resistant Mtb strains and the recent impact of the ongoing pandemic of coronavirus disease 2019 (COVID19). Examination of the immunomodulatory role of gastrointestinal microbiota presents a new direction for TB research. The gut microbiome is well-established as a critical modulator of early immune development and inflammatory responses in humans. Recent studies in animal models have further substantiated the existence of the 'gut-lung axis', where distal gastrointestinal commensals modulate lung immune function. This gut microbiome-lung immune crosstalk is postulated to have an important correlation with the pathophysiology of TB. Further evaluation of this gut immunomodulation in TB may provide a novel avenue for the exploration of therapeutic targets. This mini-review assesses the proposed mechanisms by which the gut-lung axis impacts TB susceptibility and progression. It also examines the impact of current anti-TB therapy on the gut microbiome and the effects of gut dysbiosis on treatment outcomes. Finally, it investigates new therapeutic targets, particularly the use of probiotics in treatment of antibiotic resistant TB and informs future developments in the field.

Ozone Environmental Pollution: Relationship between the Intestine and Neurodegenerative Diseases

Repeated exposure to environmental ozone causes a chronic state of oxidative stress. This state is present in chronic degenerative diseases and induces a loss of control of the inflammatory response. Redox system dysfunction and failures in control of inflammatory responses are involved in a vicious circle that maintains and increases the degenerative process. The intestine also responds to secondary reactive species formed by exposure to ozone doses, generating noxious stimuli that increase degenerative damage. This review aims to elucidate how environmental pollution, mainly by ozone, induces a state of chronic oxidative stress with the loss of regulation of the inflammatory response, both in the intestine and in the brain, where the functionality of both structures is altered and plays a determining role in some neurodegenerative and chronic degenerative diseases. For this purpose, we searched for information on sites such as the Cochrane Library Database, PubMed, Scopus, and Medscape. Reviewing the data published, we can conclude that environmental pollutants are a severe health problem. Ozone pollution has different pathways of action, both molecular and systemic, and participates in neurodegenerative diseases such as Parkinson's and Alzheimer's disease as well in bowel diseases as Inflammatory Bowel Disease, Crohn's Disease, and Irritable Bowel Syndrome.

Interactions between the lung microbiome and host immunity in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a common chronic respiratory disease and the third leading cause of death worldwide. Developments in next-generation sequencing technology have improved microbiome analysis, which is increasingly recognized as an important component of disease management. Similar to the gut, the lung is a biosphere containing billions of microbial communities. The lung microbiome plays an important role in regulating and maintaining the host immune system. The microbiome composition, metabolites of microorganisms, and the interactions between the lung microbiome and the host immunity profoundly affect the occurrence, development, treatment, and prognosis of COPD. In this review, we drew comparisons between the lung microbiome of healthy individuals and that of patients with COPD. Furthermore, we summarize the intrinsic interactions between the host and the overall lung microbiome, focusing on the underlying mechanisms linking the microbiome to the host innate and adaptive immune response pathways. Finally, we discuss the possibility of using the microbiome as a biomarker to determine the stage and prognosis of COPD and the feasibility of developing a novel, safe, and effective therapeutic target.

Differences in gut metagenomes between dairy workers and community controls: a cross-sectional study

Background

As a nexus of routine antibiotic use and zoonotic pathogen presence, the livestock farming environment is a potential hotspot for the emergence of zoonotic diseases and antibiotic resistant bacteria. Livestock can further facilitate disease transmission by serving as intermediary hosts for pathogens as they undergo evolution prior to a spillover event. In light of this, we are interested in characterizing the microbiome and resistome of dairy workers, whose exposure to the livestock farming environment places them at risk for facilitating community transmission of antibiotic resistant genes and emerging zoonotic diseases.

Results

Using shotgun sequencing, we investigated differences in the taxonomy, diversity and gene presence of the human gut microbiome of 10 dairy farm workers and 6 community controls, supplementing these samples with additional publicly available gut metagenomes. We observed greater abundance of tetracycline resistance genes and prevalence of cephamycin resistance genes in dairy workers' metagenomes, and lower average gene diversity. We also found evidence of commensal organism association with plasmid-mediated tetracycline resistance genes in both dairy workers and community controls (including Faecalibacterium prausnitzii, Ligilactobacillus animalis, and Simiaoa sunii). However, we did not find significant differences in the prevalence of resistance genes or virulence factors overall, nor differences in the taxonomic composition of dairy worker and community control metagenomes.

Conclusions

This study presents the first metagenomics analysis of United States dairy workers, providing insights into potential risks of exposure to antibiotics and pathogens in animal farming environments. Previous metagenomic studies of livestock workers in China and Europe have reported increased abundance and carriage of antibiotic resistance genes in livestock workers. While our investigation found no strong evidence for differences in the abundance or carriage of antibiotic resistance genes and virulence factors between dairy worker and community control gut metagenomes, we did observe patterns in the abundance of tetracycline resistance genes and the prevalence of cephamycin resistance genes that is consistent with previous work.

Butyrate inhibits iILC2-mediated lung inflammation via lung-gut axis in chronic obstructive pulmonary disease (COPD)

BACKGROUND

The study investigated the effects and underlying mechanisms of intestinal flora metabolite butyrate on inflammatory ILC2 cells (iILC2s)-mediated lung inflammation in chronic obstructive pulmonary disease (COPD).

METHODS

Mouse models of COPD and acute exacerbation of COPD (AECOPD) were established. Flow cytometry was used to detect natural ILC2 cells (nILC2s) and iILC2s in lung and colon tissues. The 16s rRNA and GC-MS were used to detect microbial flora and short chain fatty acids (SCFAs) in feces. ELISA was used to detect IL-13 and IL-4. Western blot and qRT-PCR were used to detect the relative protein and mRNA levels, respectively. In vitro experiments were performed with sorted ILC2s from colon tissues of control mice. Mice with AECOPD were treated with butyrate.

RESULTS

The nILC2s and iILC2s in lung and colon tissues of AECOPD mice were significantly higher than control groups. The abundance of the flora Clostridiaceae was significantly reduced, and the content of SCFAs, including acetate and butyrate, was significantly reduced. The in vitro experiments showed that butyrate inhibited iILC2 cell phenotype and cytokine secretion. Butyrate treatment reduced the proportion of iILC2 cells in the colon and lung tissues of mice with AECOPD.

CONCLUSIONS

The nILC2s and iILC2s in the colon tissues are involved in the course of COPD. Decreased Clostridiaceae and butyrate in AECOPD mice caused the accumulation of iILC2 cells in the intestines and lungs. Supplementation of butyrate can reduce iILC2 in the intestine and lung tissues. Our data may provide new ideas for prevention and treatment of COPD.

Global Research Trends on the Link Between the Microbiome and COPD: A Bibliometric Analysis

Background

The pathogenesis of chronic obstructive pulmonary disease (COPD) has been studied in relation to the microbiome, providing space for more targeted interventions and new treatments. Numerous papers on the COPD microbiome have been reported in the last 10 years, yet few publications have used bibliometric methods to evaluate this area.

Methods

We searched the Web of Science Core Collection for all original research articles in the field of COPD microbiome from January 2011 to August 2022 and used CiteSpace for visual analysis.

Results

A total of 505 relevant publications were obtained, and the number of global publications in this field is steadily increasing every year, with China and the USA occupying the first two spots in international publications. Imperial College London and the University of Leicester produced the most publications. Brightling C from the UK was the most prolific writer, while Huang Y and Sze M from the USA were first and second among the authors cited. The American Journal of Respiratory and Critical Care Medicine had the highest frequency of citations. The top 10 institutions, cited authors and journals are mostly from the UK and the US. In the ranking of citations, the first article was a paper published by Sze M on changes in the lung tissue's microbiota in COPD patients. The keywords "exacerbation", "gut microbiota", "lung microbiome", "airway microbiome", "bacterial colonization", and "inflammation" were identified as cutting-edge research projects for 2011-2022.

Conclusion

Based on the visualization results, in the future, we can use the gut-lung axis as the starting point to explore the immunoinflammatory mechanism of COPD, and study how to predict the effects of different treatments of COPD by identifying the microbiota, and how to achieve the optimal enrichment of beneficial bacteria and the optimal consumption of harmful bacteria to improve COPD.

Contribution of adaptive immunity to human COPD and experimental models of emphysema

The pathophysiology of chronic obstructive pulmonary disease (COPD) and the undisputed role of innate immune cells in this condition have dominated the field in the basic research arena for many years. Recently, however, compelling data suggesting that adaptive immune cells may also contribute to the progressive nature of lung destruction associated with COPD in smokers have gained considerable attention. The histopathological changes in the lungs of smokers can be limited to the large or small airways, but alveolar loss leading to emphysema, which occurs in some individuals, remains its most significant and irreversible outcome. Critically, however, the question of why emphysema progresses in a subset of former smokers remained a mystery for many years. The recognition of activated and organized tertiary T- and B-lymphoid aggregates in emphysematous lungs provided the first clue that adaptive immune cells may play a crucial role in COPD pathophysiology. Based on these findings from human translational studies, experimental animal models of emphysema were used to determine the mechanisms through which smoke exposure initiates and orchestrates adaptive autoreactive inflammation in the lungs. These models have revealed that T helper (Th)1 and Th17 subsets promote a positive feedback loop that activates innate immune cells, confirming their role in emphysema pathogenesis. Results from genetic studies and immune-based discoveries have further provided strong evidence for autoimmunity induction in smokers with emphysema. These new findings offer a novel opportunity to explore the mechanisms underlying the inflammatory landscape in the COPD lung and offer insights for development of precision-based treatment to halt lung destruction.

Development of severe colitis is associated with lung inflammation and pathology

Inflammatory bowel diseases (IBD) such as Crohn’s disease and ulcerative colitis are chronic relapsing diseases that affect the gastrointestinal tract, most commonly the colon. A link between the gut and the lung is suggested since patients with IBD have an increased susceptibility for chronic inflammatory lung disease. Furthermore, in the absence of overt lung disease, IBD patients have worsened lung function and more leukocytes in sputum than healthy individuals, highlighting a conduit between the gut and lung in disease. To study the gut-lung axis in the context of IBD, we used TCRδ-/- mice, which are highly susceptible to dextran sulfate sodium (DSS) due to the importance of γδ T cells in maintenance of barrier integrity. After induction of experimental colitis using DSS, the lungs of TCRδ-/- mice exhibited signs of inflammation and mild emphysema, which was not observed in DSS-treated C57BL/6 mice. Damage to the lung tissue was accompanied by a large expansion of neutrophils in the lung parenchyma and an increase in alveolar macrophages in the lung wash. Gene expression analyses showed a significant increase in Csf3, Cxcl2, Tnfa, and Il17a in lung tissue in keeping with neutrophil infiltration. Expression of genes encoding reactive oxygen species enzymes and elastolytic enzymes were enhanced in the lungs of both C57BL/6 and TCRδ-/- mice with colitis. Similarly, surfactant gene expression was also enhanced, which may represent a protective mechanism. These data demonstrate that severe colitis in a susceptible genetic background is sufficient to induce lung inflammation and tissue damage, providing the research community with an important tool for the development of novel therapeutics aimed at reducing co-morbidities in IBD patients.

Targeting Lung-Gut Axis for Regulating Pollution Particle-Mediated Inflammation and Metabolic Disorders

Cigarette smoking (CS) or ambient particulate matter (PM) exposure is a risk factor for metabolic disorders, such as insulin resistance (IR), increased plasma triglycerides, hyperglycemia, and diabetes mellitus (DM); it can also cause gut microbiota dysbiosis. In smokers with metabolic disorders, CS cessation decreases the risks of serious pulmonary events, inflammation, and metabolic disorder. This review included recent studies examining the mechanisms underlying the effects of CS and PM on gut microbiota dysbiosis and metabolic disorder development; one of the potential mechanisms is the disruption of the lung-gut axis, leading to gut microbiota dysbiosis, intestinal dysfunction, systemic inflammation, and metabolic disease. Short-chain fatty acids (SCFAs) are the primary metabolites of gut bacteria, which are derived from the fermentation of dietary fibers. They activate G-protein-coupled receptor (GPCR) signaling, suppress histone deacetylase (HDAC) activity, and inhibit inflammation, facilitating the maintenance of gut health and biofunction. The aforementioned gut microbiota dysbiosis reduces SCFA levels. Treatment targeting SCFA/GPCR signaling may alleviate air pollution-associated inflammation and metabolic disorders, which involve lung-gut axis disruption.

Short chain fatty acids: key regulators of the local and systemic immune response in inflammatory diseases and infections

The human intestinal microbiome substantially affects human health and resistance to infections in its dynamic composition and varying release of microbial-derived metabolites. Short-chain fatty acids (SCFA) produced by commensal bacteria through fermentation of indigestible fibres are considered key regulators in orchestrating the host immune response to microbial colonization by regulating phagocytosis, chemokine and central signalling pathways of cell growth and apoptosis, thereby shaping the composition and functionality of the intestinal epithelial barrier. Although research of the last decades provided valuable insight into the pleiotropic functions of SCFAs and their capability to maintain human health, mechanistic details on how SCFAs act across different cell types and other organs are not fully understood. In this review, we provide an overview of the various functions of SCFAs in regulating cellular metabolism, emphasizing the orchestration of the immune response along the gut-brain, the gut-lung and the gut-liver axes. We discuss their potential pharmacological use in inflammatory diseases and infections and highlight new options of relevant human three-dimensional organ models to investigate and validate their biological functions in more detail.

Selenium-enriched foods and their ingredients: As intervention for the vicious cycle between autophagy and overloaded stress responses in Alzheimer's disease

Dysfunctional autophagy induced by excessive reactive oxygen species (ROS) load and inflammation accelerates the development of Alzheimer's disease (AD). Recently, there has been an increasing interest in selenium-enriched ingredients (SEIs), such as selenoproteins, selenoamino acids and selenosugars, which could improve AD through antioxidant and anti-inflammation, as well as autophagy modulating effects. This review indicates that SEIs eliminate excessive ROS by activating the nuclear translocation of nuclear factor erythroid2-related factor 2 (Nrf2) and alleviate inflammation by inhibiting the mitogen-activated protein kinases (MAPKs)/nuclear factor kappa-B (NF-κB) pathway. Furthermore, they can activate the adenosine 5'-monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway, and subsequently promote amyloid beta (Aβ) clearance and reduce memory impairments. SEIs are ubiquitous in many plants and microorganisms, such as Brassicaceae vegetables, yeast, and mushroom. Enzymatic hydrolysis, as well as physical processing, such as thermal, high pressure and microwave treatment, are the main techniques to modify the properties of dietary selenium. This work highlights the fact that SEIs can inhibit inflammation and oxidative stress and provides evidence that supports the potential use of these dietary materials to be a novel strategy for improving AD.

Virulence factors and mechanisms of paediatric pneumonia caused by Enterococcus faecalis

Paediatric pneumonia is a respiratory infection that affects infants and young children under the age of 3. This disease is the leading cause of infant and child mortality in developing countries because of the weak immune system of young children. The difficulty and length of time required to identify the pathogen and causative agent are the main reasons for this high mortality rate. In addition, the identification of certain causative agents is particularly important for the treatment of paediatric pneumonia. In this study, we explored the possible mechanisms by which pathogenic Enterococcus faecalis induced pneumonia in vivo. The potential virulence factors of bacteria isolated from the intestines of paediatric pneumonia patients were determined. Taken together, the results suggested that lysophosphatidic acid (LTA) from pathogenic E. faecalis decreases the expression of platelet-activating factor receptor (PAFR), which in turn disrupts the function of intestinal tight junctions (Occ and Ccldn1), leading to the entry of LE-LTA into the bloodstream because of the disruption of the intestinal barrier. Although LTA can enter circulation, it cannot directly infiltrate the lungs, which indicates that lung inflammation in mice is not caused by the direct entry of LE-LTA into the lungs. We further found that LTA activates immune cells, such as CD8 + T cells and type 2 innate lymphocytes, in vivo. Interleukin-6 and interleukin-17 can produce large amounts of inflammatory factors and thus promote the development of pneumonia. In conclusion, our findings demonstrate that the LTA of pathogenic E. faecalis in the intestine is a virulence factor that can cause paediatric pneumonia. This study found that intestinal bacterial virulence factors can induce immune responses in the lungs and blood. These findings could provide further insight into the mechanism of infectious diseases in the lung that are caused by bacteria in the intestine.

Implementation of screening criteria for inflammatory bowel disease in patients with spondyloarthritis and its association with disease and endoscopic activity

There is little literature on the implementation of screening criteria for inflammatory bowel disease (IBD) in patients with spondyloarthritis (SpA). This study aimed to apply IBD screening criteria in a group of patients with SpA without IBD diagnosis and correlate them to endoscopic findings and disease activity. A total of 82 patients with SpA were included. The IBD screening test and ileocolonoscopy with digital chromoendoscopy with magnification and histological analysis were performed. The data were analysed with Chi-square test/Fisher's exact test and multiple correspondence analysis. The major screening criteria found in 48.7% of the patients were associated with a history of infection (p = 0.037). Rectal bleeding was associated with the diagnosis of ankylosing spondylitis, acute inflammation, enthesitis and tissue architecture alteration in the ileum (p < 0.050). Diarrhoea was associated with a higher disease activity score (p = 0.02). Minor screening criteria were associated with painful inflammatory joint (p = 0.05), high disease activity score (p = 0.001) and high calprotectin levels (p = 0.050). Abdominal pain (36.9%) was associated with axial/peripheral compromise (p = 0.017), inflammatory back pain (p = 0.01), enthesitis (p = 0.021), higher disease activity score (p = 0.023) and acute ileum inflammation (p = 0.046). Diarrhoea of 4 weeks and abdominal pain were the most prevalent major and minor screening criteria, respectively, being related to early manifestations of inflammatory bowel compromise and higher disease activity score. This screening test grants a chance of opportune referral of SpA patients from rheumatology to gastroenterology.