Article Text
Abstract
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.
- emphysema
- COPD pathology
Data availability statement
The data that support the findings of this study are available from the corresponding author (SWL), upon reasonable request.
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Data availability statement
The data that support the findings of this study are available from the corresponding author (SWL), upon reasonable request.
Footnotes
SHL and JK are joint first authors.
SHL and JK contributed equally.
Contributors SWL developed the concept and designed the experiment. SWL and YJ enrolled participants and collected clinical samples. JK, SHL and SWL developed the image reconstruction and analysis methods used in the study. JK, NHK, O-HK, C-HS and S-HH performed animal experiments. SJK and HJY performed metabolome analysis. SY, SEL and SYJ performed microbiome analysis. SHL, JK and SWL wrote the first draft of the manuscript and all authors contributed to redrafting the manuscript. The guarantor is SWL.
Funding This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. 2020R1A2C1008431, 2023R1A2C2006688, RS-2023-00222687, SWL), Basic Science Research Program through the NRF of Korea funded by the Ministry of Education (No. 2020R1I1A1A01069464, JK) and the Bio & Medical Technology Development Program of NRF funded by the Korean government (MSIT) (No. 2022M3A9G8017220).
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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