Gut microbiota composition and metabolite profiling in smokers: a comparative study between emphysema and asymptomatic individuals with therapeutic implications.

BACKGROUND: Diet has a crucial role in the gut microbiota, and dysbiosis in the gut and lungs has been suggested to be associated with chronic obstructive pulmonary disease. We compared the diet, microbiome and metabolome between asymptomatic smokers and those with emphysema. METHODS: We enrolled 10 asymptomatic smokers with preserved lung function and 16 smokers with emphysema with severe airflow limitation. Dietary intake information was gathered by a self-reported questionnaire. Sputum and faecal samples were collected for microbial and metabolomics analysis. A murine model of emphysema was used to determine the effect of metabolite supplementation. RESULTS: Despite having a similar smoking history with emphysema patients, asymptomatic smokers had higher values of body mass index, fibre intake and faecal acetate level. Linear discriminant analysis identified 17 microbial taxonomic members that were relatively enriched in the faeces of asymptomatic smokers. Analysis of similarity results showed dissimilarity between the two groups (r=0.287, p=0.003). Higher acetate level was positively associated with forced expiratory volume in one second in the emphysema group (r=0.628, p=0.012). Asymptomatic smokers had a greater number of species associated with acetate and propionate (r>0.6) than did those with emphysema (30 vs 19). In an emphysema mouse model, supplementation of acetate and propionate reduced alveolar destruction and the production of proinflammatory cytokines, and propionate decreased the CD3+CD4+IL-17+ T-cell population in the lung and spleen. CONCLUSION: Smokers with emphysema showed differences in diet, microbiome and short-chain fatty acids compared with asymptomatic smokers. Acetate and propionate showed therapeutic effects in a smoking-induced murine model of emphysema.

The impact of ambient air pollution on lung function and respiratory symptoms in elite athletes.

BACKGROUND: Air pollution has become a significant public health concern. During exercise, many physiological factors are thought to increase the effects of air pollution. Air pollution most affects lung function and respiratory symptoms. We investigated the association between lung function, respiratory symptoms, and air pollutant concentration with meteorological factors in elite sports athletes. METHODS: A total of 59 elite sports athletes from the Korea National Sports University participated in this prospective, observational study from September 2019 to June 2020. At ten visits, lung function and respiratory symptoms were obtained after a training session. We measured six air pollutants, including SO2, CO, O3, NO2, PM10, and PM2.5, and two meteorological factors, including humidity and temperature. Air pollutants and meteorological factors were measured by two nearest depositories of the national air pollution information system in Korea. RESULTS: In a single-pollutant model, PM2.5, PM10, NO2, and CO were inversely associated with both FEV1 and FEV6, 10 µg/m3 in PM2.5 was associated with a 32.31 mL decrease in FEV1 and a 36.93 mL decrease in FEV6. Meanwhile, O3 and temperature had positive associations with both FEV1 (13.00 and 3.15 mL) and FEV6 (16.91 and 4.76 mL) and humidity with FEV6 (11.98 mL). In the multi-pollutant model at lag 0, FEV1 was associated negatively with O3 and NO2 (-50.68 and -6.87 mL) and positively with SO2 and temperature (65.76 and 8.08 mL). In the multi-pollutant model at lag 6, temperature was associated with FEV1 and FEV6 (6.01 and 8.89 mL). PM2.5, PM10, NO2, CO, and temperature were significantly associated with FEV1 and FEV6 through lag 0-6. CONCLUSIONS: Air pollutants and meteorological factors are associated with lung function and respiratory symptoms and have cumulative effects among elite athletes. In the multi-pollutant model, temperature has the most significant effect on lung function.

Randomised controlled trial of a behavioural intervention to reduce exposure to PM2.5 in patients with COPD.

BACKGROUND: Fine particulate matter (PM2.5) is a well-known risk factor for worse outcomes of chronic obstructive pulmonary disease (COPD). However, evidence-based guidance on effective personal behavioural strategies to minimise the effects of PM2.5 is limited. This study aimed to assess the effectiveness of a behavioural intervention in reducing PM2.5 exposure and improving clinical outcomes in patients with COPD. MATERIALS AND METHODS: Participants were 1:1 randomised, and the intervention group received a behavioural intervention consisting of five activities, while the control group received usual care. The participants were followed up for 9 months. The primary outcomes were differences in the score of St. George's Respiratory Questionnaire for patients with COPD (SGRQ-C) and COPD assessment test (CAT) from baseline. RESULTS: A total of 106 participants were enrolled and 102 completed the study. At the end of the study, the intervention group showed significant improvements in the primary outcomes compared to the control group, with a group difference of -5.9 in the reduction of total SGRQ-C (-3.4 vs. 2.5; p = 0.049) and -3.8 in the CAT score (-1.2 vs. 2.7; p = 0.001). Participants with good adherence to the intervention demonstrated a greater extent of improvement in CAT score and lower PM2.5 levels compared to those who had poor adherence or were in the control group. Regular checking of air quality forecasts was significantly associated with a reduction in CAT scores among all the intervention activities. CONCLUSION: Individual-level behavioural interventions can be an effective strategy for mitigating the health hazards associated with PM2.5. CLINICALTRIALS: gov Identifier: NCT04878367.

Gene-Based Diagnosis of Tuberculosis from Oral Swabs with a New Generation Pathogen Enrichment Technique.

A rapid and sensitive diagnosis is crucial for the management of tuberculosis (TB). A simple and label-free approach via homobifunctional imidoesters with a microfluidic platform (SLIM) assay showed a higher sensitivity than the Xpert MTB/RIF assay in the diagnosis of pulmonary TB (PTB). Here, we evaluated the efficacy of the SLIM assay for oral swab samples from cases of suspected PTB. Patients with clinically suspected PTB were prospectively enrolled and oral swab samples were processed using the SLIM assay and the attending physicians were blinded to the results of the SLIM assay. TB cases were defined as those treated with anti-TB chemotherapy for at least 6 months at the discretion of the specialists based on their clinical features and conventional laboratory results, including the Xpert assay. A total of 272 patients (with TB, n = 128 [47.1%]; without TB, n = 144 [52.9%]; mean age, 59.8 years) were enrolled. Overall, the sensitivity of the oral swab-based SLIM assay (65.6%) was higher than that of the sputum-based Xpert assay (43.4%; P = 0.001). Specifically, the SLIM oral swab assay showed a notably higher sensitivity in culture-negative TB cases compared with the Xpert assay (69.0% [95% CI: 49.2 to 84.7%] versus 7.4% [95% CI: 0.9 to 24.3%]; P = 0.001). The specificity of the SLIM and the Xpert assays was 86.1% (95% CI: 79.3 to 91.3%) and 100% (95% CI: 97.2 to 100%), respectively. When only culture-confirmed cases were analyzed, the SLIM oral swab was comparable to sputum Xpert in sensitivity (64.7% versus 54.3%, P = 0.26). The oral swab-based SLIM assay showed a superior sensitivity for TB diagnosis over the sputum-based Xpert assay, especially for culture-negative cases. IMPORTANCE The development of a rapid, accessible, and highly sensitive diagnostic tool is a major challenge in the control and management of tuberculosis. Gene-based diagnostics is recommended for the rapid diagnosis of pulmonary tuberculosis (PTB), but its sensitivity, such as Xpert MTB/RIF assay (Xpert), drops in cases with a low bacterial load. It can only be applied to sputum samples, and it is quite difficult for some patients to produce an adequate amount of sputum. We evaluated the clinical validity of an oral swab-based microfluidic system, i.e., the SLIM assay. The SLIM assay showed a significantly higher sensitivity than the Xpert assay, especially in smear-negative TB cases. This non-sputum-based SLIM assay can be a useful diagnostic test by overcoming the limitations of conventional sputum-based tests in pulmonary TB.

Efficacy of Unsupervised Home-Based Pulmonary Rehabilitation for Patients with Chronic Obstructive Pulmonary Disease.

Purpose: Pulmonary rehabilitation (PR) is a well-established treatment for chronic obstructive pulmonary disease (COPD). The standard protocol for PR requires frequent hospital visits, which can be difficult for patients. We performed this study to assess whether unsupervised home-based PR (HBPR) is effective for patients with COPD. Patients and Methods: After assessing the outcome data, including the results of a COPD assessment test (CAT); the body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index; a spirometry; the modified Medical Research Council (mMRC) dyspnea scale; and the 6-min walking test (6MWT), specialists imparted 1-hour education to patients regarding unsupervised HBPR at the baseline visit. This included methods for breathing, inhaler use, stretching, and exercise. On reviewing diaries after 8 weeks from the first visit, patients who exercised at least thrice per week were classified as the compliant group and the others were categorized as the noncompliant group. Changes in the outcomes were compared between the compliant and noncompliant groups. Results: A total of 41 patients were enrolled in this study; for 8 weeks of unsupervised HBPR, there were significant improvements in CAT scores (-4.62±4.61 vs 2.40±6.73; P=0.002), BODE index (-1.00±1.06 vs -0.20±0.56; P=0.01), and forced expiratory volume in 1 s (0.05±0.19 vs -0.09±0.16; P=0.02) among patients in the compliant group, compared with the noncompliant group. Moreover, their CAT (16.46±7.80 vs 11.85±7.23; P=0.03) and mMRC scores (2.54±0.76 vs 1.81±0.63; P=0.001) improved significantly after 8 weeks, compared with those at baseline. On the other hand, patients in the noncompliant group showed no significant improvement in any of the outcomes. Conclusion: In this study, compliant patients with unsupervised HBPR achieved favorable outcomes in 8 weeks. Thus, we recommend unsupervised HBPR for patients with COPD, even when regular hospital visits for PR are not possible. Trial Registration: NCT03754881.