Data and code from: Plasma short-chain fatty acids are associated with COPD and COPD phenotypes

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.