Data and code from: Plasma short-chain fatty acids are associated with COPD and COPD phenotypes
Data files
Jun 10, 2026 version files 91.98 KB
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metadata_share.csv
27.40 KB
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nonimputed_data.csv
15.99 KB
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README.md
2.43 KB
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script_share.R
46.16 KB
Abstract
Short-chain fatty acids (SCFAs) are metabolites produced by gut microbiota and may influence COPD development by modulating the immune system. This study examined the relationship between circulating SCFA concentrations and COPD and COPD phenotypes. We report findings from a single-centre case-control study with 130 COPD patients and 103 controls. Eight SCFAs (α-methylbutyrate, valerate, propionate, isovalerate, isobutyrate, formate, butyrate, and acetate) were quantified in plasma using isotope-labelled gas chromatography-tandem mass spectrometry. Associations between SCFAs, COPD status, and COPD phenotypes (severely obstructive COPD, emphysema, eosinophilic COPD, frequent exacerbations, and symptom burden) were evaluated using multivariable regression analyses adjusted for age, sex, smoking, and body composition. Plasma formate concentrations were inversely associated with COPD status (adjusted OR 0.33; 95 % CI 0.15 to 0.66; p = 0.004). Propionate and isobutyrate concentrations were inversely associated with severely obstructive COPD (adjusted ORs 0.46; 95 % CI 0.24 to 0.86; p = 0.018, and 0.33; 95 % CI 0.14 to 0.75; p = 0.012, respectively). Propionate concentrations were also inversely associated with frequent exacerbations of COPD (adjusted OR 0.23; 95 % CI 0.07 to 0.62; p = 0.007). Isovalerate was positively associated with symptom burden (CAT score) (estimate 1.76; 95 % CI 0.20 to 3.32; p = 0.027). No consistent associations were observed for emphysema or eosinophilic COPD. SCFA formate was inversely related to COPD. Several SCFAs were associated with specific COPD phenotypes. Future studies should investigate the underlying mechanisms linking SCFAs to COPD and include the often-overlooked formate, while acknowledging formate’s dual origin.
Dataset DOI: 10.5061/dryad.mw6m9069h
Description of the data and file structure
Describes the files stored at DRYAD for the paper “Plasma concentrations of short-chain fatty acids are associated with COPD and COPD phenotypes” by Rotevatn et al.
This note is written by Anders Rotevatn, 18 November 2025.
Files and variables
File: nonimputed_data.csv
Description:
This file contains the short-chain fatty acid concentrations in plasma (in µmol/L):
Variables
- ID_mock: ID number for DRYAD
- Frm: Formate
- Ace: Acetate
- Pro: Propionate
- But: Butyrate
- iBut: Isobutyrate
- Vlr: Valerate
- iVlr: Isovalerate
- aMB: alpha-Methylbutyrate
File: metadata_share.csv
Description:
This file contains the metadata with following variables:
Variables
- ID_mock: ID number made for DRYAD to match with the SCFA concentrations
- Diagnosis: COPD or Controls
- AgeGroup: Age in groups of 10 years. We used age as a continuous variable in the original analysis, but the age variable is converted here in order to maintain anonymity for participants
- Sex: 0/1
- smoking: never/former/current
- bodycomp2_926: Body composition: normal/cachexia/obese (measured by bioelectrical impedance measurements)
- fvc_pct: Spirometry - forced vital capacity (per cent predicted)
- fev1_pct: Spirometry - Forced expiratory volume 1 second (per cent predicted)
- fev1fvcratio: Ratio FEV1/ FVC
- eosinophile_03: Blood eosinophils ≥ 0.3 109 cells/L
- emphysema: 0- / 10-; < / >= 10 % low attenuating areas, treshold < -950 Hounsfield units on CT thorax scan
- GOLD_stage: COPD GOLD stage as defined by FEV1 (% predicted) ≥ 80 % (I) / 50-79 % (II) / 30-49 % (III)/ < 30 % (IV), grouped into GOLD stage 1-2 and 3-4
- copd_exacerbations: Number of COPD exacerbations during the previous 12 months; 0-1 / ≥ 2
- cat_score: COPD assessment test score
File: script_share.R
Description: R script for the analyses for the publication based on these data.
Code/software
R, version 4.5
Human subjects data
Data are fully anonymized, including creation of a new ID number only for this dataset. All participants gave informed consent for publication prior to study inclusion. Sex is given only as 0-1 and age in 10 year cohorts.