Integrated metagenomic and metabolomic analysis of Chinese COPD patients revealed marked gut microbiota compositional and functional alterations, with serum eremopetasinorol showing high diagnostic accuracy (AUC = 0.947) and reduced serum riboflavin levels positively correlating with pulmonary function indices.
Key Findings
Results
Alpha diversity of gut microbiota did not differ significantly between COPD patients and healthy controls, whereas beta diversity showed clear separation between the two groups.
Study included 74 stable COPD patients and 30 healthy controls from northern China
Shotgun metagenomic sequencing was used, providing higher resolution than 16S rRNA sequencing
Beta diversity analysis demonstrated distinct clustering between COPD and healthy control groups
Alpha diversity metrics (richness/evenness) were comparable between groups despite compositional differences
Results
Marked differences in microbial composition were observed in COPD patients from phylum to species levels, including the family Oscillospiraceae.
Compositional differences spanned multiple taxonomic levels from phylum down to species
Oscillospiraceae was specifically identified as a differentially represented taxon
Altered microbial functions included signal transduction and antibiotic resistance pathways
High-resolution shotgun metagenomic sequencing enabled species-level characterization not possible with standard 16S rRNA approaches
Results
Metabolomic profiling identified 497 differential fecal metabolites and 1260 differential serum metabolites in COPD patients compared to healthy controls.
Untargeted metabolomics was performed on both fecal and serum samples
497 differential metabolites were identified in fecal samples
1260 differential metabolites were identified in serum samples
Serum metabolomics yielded more than twice the number of differential metabolites compared to fecal metabolomics
Results
Serum riboflavin levels were significantly reduced in COPD patients and positively correlated with pulmonary function indices and the key differential gut microbial functional gene K11752.
Riboflavin (vitamin B2) was identified as a significantly reduced serum metabolite in COPD patients
Serum riboflavin showed positive correlation with pulmonary function indices
A positive correlation was found between serum riboflavin and microbial functional gene K11752
This finding suggests a potential gut microbiota-metabolite-lung function axis involving riboflavin metabolism
Results
The serum metabolite eremopetasinorol exhibited high diagnostic accuracy for COPD with an AUC of 0.947 (95% CI: 0.8–0.98), surpassing fecal metabolites and microbial features as a diagnostic marker.
AUC = 0.947 with 95% confidence interval of 0.8 to 0.98
Eremopetasinorol outperformed fecal metabolites in diagnostic accuracy
Eremopetasinorol also surpassed microbial features (composition/functional genes) in diagnostic performance
Serum-based metabolite markers demonstrated superior diagnostic utility compared to gut-based markers in this cohort
Background
Most prior COPD gut microbiota studies relied on low-resolution 16S rRNA sequencing, and integrated multi-omics investigations in Chinese COPD populations were scarce prior to this study.
The gut-lung axis is recognized as important in COPD pathogenesis
This study used shotgun metagenomic sequencing for higher taxonomic and functional resolution
The study recruited participants specifically from northern China, addressing a gap in Chinese population data
The integrated metagenomic and metabolomic approach provides novel insights for biomarker discovery and targeted intervention strategies
What This Means
This research suggests that the bacteria living in the gut of people with Chronic Obstructive Pulmonary Disease (COPD) — a serious lung disease — are meaningfully different from those in healthy people, both in terms of which species are present and what those bacteria are doing biochemically. The researchers studied 74 stable COPD patients and 30 healthy people from northern China using advanced DNA sequencing of gut bacteria and chemical profiling of stool and blood samples. They found that while the overall variety of gut bacteria was similar between groups, the specific composition was clearly different, and COPD patients had hundreds of altered chemical compounds (metabolites) in both their stool and blood.
Two particularly notable findings emerged from the blood metabolite analysis. First, levels of riboflavin (vitamin B2) in the blood were significantly lower in COPD patients and were linked to worse lung function, suggesting a potential connection between gut bacterial activity, riboflavin production or absorption, and lung health. Second, a compound called eremopetasinorol in the blood showed remarkable ability to distinguish COPD patients from healthy individuals, with a diagnostic accuracy score (AUC) of 0.947 out of 1.0, which is considered very high and outperformed other markers tested including stool metabolites and bacterial composition data.
This research suggests that the gut-lung connection in COPD is real and measurable through blood and stool testing, and that certain blood-based chemical markers may eventually help doctors diagnose or monitor COPD more accurately. The findings also raise the possibility that targeting gut bacteria or nutritional factors like riboflavin could be explored as part of future COPD management strategies, though further research would be needed to confirm these connections and their clinical usefulness.
Wang Y, Liu X, Gao R, An Y, Ren C, An L. (2026). Characteristics of Gut Microbiota in Patients with Chronic Obstructive Pulmonary Disease Based on Metagenomics and Metabolomics.. International journal of molecular sciences. https://doi.org/10.3390/ijms27104213