Microbiome Links Cigarette Smoke-Induced Chronic Obstructive Pulmonary Disease and Dietary Fiber via the Gut-Lung Axis: A Narrative Review

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.

Modulation of chronic obstructive pulmonary disease progression by antioxidant metabolites from Pediococcus pentosaceus: enhancing gut probiotics abundance and the tryptophan-melatonin pathway

Chronic obstructive pulmonary disease (COPD), a condition primarily linked to oxidative stress, poses significant health burdens worldwide. Recent evidence has shed light on the association between the dysbiosis of gut microbiota and COPD, and their metabolites have emerged as potential modulators of disease progression through the intricate gut-lung axis. Here, we demonstrate the efficacy of oral administration of the probiotic Pediococcus pentosaceus SMM914 (SMM914) in delaying the progression of COPD by attenuating pulmonary oxidative stress. Specially, SMM914 induces a notable shift in the gut microbiota toward a community structure characterized by an augmented abundance of probiotics producing short-chain fatty acids and antioxidant metabolisms. Concurrently, SMM914 synthesizes L-tryptophanamide, 5-hydroxy-L-tryptophan, and 3-sulfino-L-alanine, thereby enhancing the tryptophan-melatonin pathway and elevating 6-hydroxymelatonin and hypotaurine in the lung environment. This modulation amplifies the secretion of endogenous anti-inflammatory factors, diminishes macrophage polarization toward the M1 phenotype, and ultimately mitigates the oxidative stress in mice with COPD. The demonstrated efficacy of the probiotic intervention, specifically with SMM914, not only highlights the modulation of intestine microbiota but also emphasizes the consequential impact on the intricate interplay between the gastrointestinal system and respiratory health.

Seabuckthorn Wuwei Pulvis attenuates chronic obstructive pulmonary disease in rat through gut microbiota-short chain fatty acids axis

ETHNOPHARMACOLOGICAL RELEVANCE

Seabuckthorn Wuwei Pulvis (SWP) is a traditional Mongolian medicine used in China. It is composed of Hippophae rhamnoides (berries, 30 g), Aucklandiae costus Falc. (dry root, 25 g), Vitis vinifera F. Cordifolia (berries, 20 g), Glycyrrhiza uralensis Fisch. (dry root, 15 g), and Gardenia jasminoides J. Ellis (desiccative ripe fruit, 10 g). It is clinically applied in the treatment of chronic cough, shortness of breath and phlegm, and chest distress. Past studies demonstrated that Seabuckthorn Wuwei Pulvis improved lung inflammation and chronic bronchitis in mice. However, the effect of Seabuckthorn Wuwei Pulvis on chronic obstructive pulmonary disease (COPD) in rats and the underlying action mechanism is not fully understood.

AIM OF THE STUDY

To evaluate the anti-COPD effect of Seabuckthorn Wuwei Pulvis and investigate whether its ameliorative effect is correlated with the composition of gut microbiota and its metabolites.

MATERIALS AND METHODS

The effects of Seabuckthorn Wuwei Pulvis on a COPD rat model were established by exposure to lipopolysaccharide (LPS) and smoking. These effects were then evaluated by monitoring the animal weight, pulmonary function, lung histological alteration, and the levels of inflammatory factors (tumor necrotic factor [TNF]-α, interleukin [IL]-8, IL-6, and IL-17). Furthermore, the serum LPS and fluorescein isothiocyanate-dextran levels were detected by using an enzyme-linked immunosorbent assay and fluorescence microplate reader, respectively. Tight junction proteins (ZO-1 and occludin-1) in the small intestine were detected by performing real-time quantitative polymerase chain reactions and Western blotting to evaluate the intestinal barrier function. The contents of short-chain fatty acids (SCFAs) in the feces of rats were determined by gas chromatography-mass spectrometry. 16S rDNA high throughput sequencing was used to investigate the effect of SWP on the gut microbiota of COPD rats.

RESULTS

Treatment with low and median doses of SWP significantly increased the pulmonary function (forced expiratory volume [FEV] 0.3, forced vital capacity [FVC], and FEV0.3/FVC), decreased the levels of TNF-α, IL-8, IL-6, and IL-17 in the lung, and attenuated the infiltration of inflammatory cells into the lung. The low and median doses of SWP shaped the composition of gut microbiota, which increased the abundances of Ruminococcaceae, Christensenellaceae, and Aerococcaceae, increased the productions of acetic acid, propionic acid, and butyric acid, and upregulated the expression of ZO-1 and occludin-1 in the small intestine of COPD rats.

CONCLUSION

SWP improved pulmonary functions and inhibited the inflammatory response by shaping the gut microbiota, increasing SCFA production, and strengthening the intestinal barrier function in rats with COPD induced by LPS and smoking.

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.

Airway microbiome-immune crosstalk in chronic obstructive pulmonary disease

Chronic Obstructive Pulmonary Disease (COPD) has significantly contributed to global mortality, with three million deaths reported annually. This impact is expected to increase over the next 40 years, with approximately 5 million people predicted to succumb to COPD-related deaths annually. Immune mechanisms driving disease progression have not been fully elucidated. Airway microbiota have been implicated. However, it is still unclear how changes in the airway microbiome drive persistent immune activation and consequent lung damage. Mechanisms mediating microbiome-immune crosstalk in the airways remain unclear. In this review, we examine how dysbiosis mediates airway inflammation in COPD. We give a detailed account of how airway commensal bacteria interact with the mucosal innate and adaptive immune system to regulate immune responses in healthy or diseased airways. Immune-phenotyping airway microbiota could advance COPD immunotherapeutics and identify key open questions that future research must address to further such translation.

The therapeutic potential of quercetin for cigarette smoking-induced chronic obstructive pulmonary disease: a narrative review

Quercetin is a flavonoid with antioxidant and anti-inflammatory properties. Quercetin has potentially beneficial therapeutic effects for several diseases, including cigarette smoking-induced chronic obstructive pulmonary disease (CS-COPD). Many studies have shown that quercetin's antioxidant and anti-inflammatory properties have positive therapeutic potential for CS-COPD. In addition, quercetin's immunomodulatory, anti-cellular senescence, mitochondrial autophagy-modulating, and gut microbiota-modulating effects may also have therapeutic value for CS-COPD. However, there appears to be no review of the possible mechanisms of quercetin for treating CS-COPD. Moreover, the combination of quercetin with common therapeutic drugs for CS-COPD needs further refinement. Therefore, in this article, after introducing the definition and metabolism of quercetin, and its safety, we comprehensively presented the pathogenesis of CS-COPD related to oxidative stress, inflammation, immunity, cellular senescence, mitochondrial autophagy, and gut microbiota. We then reviewed quercetin's anti-CS-COPD effects, performed by influencing these mechanisms. Finally, we explored the possibility of using quercetin with commonly used drugs for treating CS-COPD, providing a basis for future screening of excellent drug combinations for treating CS-COPD. This review has provided meaningful information on quercetin's mechanisms and clinical use in treating CS-COPD.

Deducing the Interplay Between Gut Flora and Respiratory Diseases: A New Therapeutic Strategy?

The gastrointestinal system, also referred to as the gut, is a universe that colonizes trillions of microbes. In addition to its digestive functions, the gut represents a biosystem that determines all the health vectors. It is now recognized as one of the body's defense systems, and good gut health regulates the body's immune responses. Disturbance of this barrier can trigger many diseases, including respiratory tract infections, as there is a close correlation between the gut microbiome and the chances of triggering illness. This review investigates the various factors affecting the gut microbiome, the diseases that can result from the dysregulation of the same, and their molecular mechanisms. The most basic solution to tackle this problem is to maintain the gut microbiome at the desired level. Timely diagnosis and interventions are needed for the proper management of the ensuing conditions. It is important to address the effects of factors on the gut microbiome and thereby regulate this level. The study also found that dysregulation in the system can lead to various diseases such as asthma, COPD, lung cancer following their respective pathways. In short, this paper reinforces the importance of the gut microbiome, the need to maintain its average level, and the need for proper interventions to treat the consequences. The manuscript posit that medications, diet as well and good physiological conditions of the human body can alter the microbiome and can ward off respiratory infections.

Gut-Lung Microbiota Interaction in COPD Patients: A Literature Review

Respiratory diseases are one of the leading causes of death in the world, which is why a lot of attention has been recently paid to studying the possible mechanisms for the development of pulmonary diseases and assessing the impact on their course. The microbiota plays an important role in these processes and influences the functionality of the human immune system. Thus, alterations in the normal microflora contribute to a reduction in immunity and a more severe course of diseases. In this review, we summarized the information about gut and lung microbiota interactions with particular attention to their influence on the course of chronic obstructive pulmonary disease (COPD).

A quasi-experimental study of the effect of a comprehensive blended health educational program on self-management practices among patients with chronic obstructive pulmonary disease

BACKGROUND

The prevalence and illness burden of chronic obstructive pulmonary disease (COPD) are both high. Currently, limited guidance is available to support the establishment of effective health programs to increase self-management practices in patients with COPD.

OBJECTIVES

To explore the effect of a comprehensive blended health education program on self-management practices in patients with mild-to-moderate COPD in Jeddah City, Saudi Arabia.

METHODS

A quasi-experimental research study was carried out with a convenience sample of 60 discharged or stable patients with COPD following treatment. Participants were divided into an intervention group (n = 30) that received usual hospital care and blended health education program, and a control group (n = 30) that obtained the usual hospital care without involvement in the health education program from May 2021- to August 2021. Data were collected before and three months after the intervention using the COPD Self-Management Scale and patient socio-demographic and clinical information surveys.

RESULTS

Statistically significant differences were found between the control and intervention groups after three months of the intervention based on total COPD Self-Management Scale scores. There were no statistically significant relationships between the participants' mean COPD Self-Management Scale scores in both groups with their socio-demographic and clinical characteristics before and after the intervention.

CONCLUSIONS

A nurse-led, comprehensive blended health education program was found to be an effective method for improving COPD patients' self-management practices. COPD nurses and nurse researchers must collaborate to identify the most common interventions with the best cost/benefit ratios and greater positive effects on early COPD patients' self-management practices and general well-being.