Gut-Lung Axis in COPD: Investigating the Impact of Dietary Fiber Intake on Systemic Inflammation and Lung Function Decline.

COPD patients had significantly lower dietary fiber intake compared to healthy controls.

• COPD patients consumed 18.30 ± 6.20 g/day of dietary fiber versus 28.70 ± 8.10 g/day in controls (P < 0.001).
• Study included 100 COPD patients and 100 age- and sex-matched healthy controls in a case-control design.
• Dietary fiber intake was assessed using a validated food frequency questionnaire.

Systemic inflammatory markers CRP and IL-6 were significantly elevated in COPD patients compared to controls.

• CRP levels were 5.80 ± 3.20 mg/L in COPD patients versus 1.20 ± 0.80 mg/L in controls (P < 0.001).
• IL-6 levels were 8.40 ± 4.10 pg/mL in COPD patients versus 2.10 ± 1.30 pg/mL in controls (P < 0.001).
• Inflammatory markers were measured by ELISA.

Dietary fiber intake was inversely correlated with systemic inflammatory markers in COPD patients.

• Dietary fiber intake was inversely correlated with CRP (r = -0.52, P < 0.001).
• Dietary fiber intake was inversely correlated with IL-6 (r = -0.48, P < 0.001).

Dietary fiber intake was positively correlated with lung function parameters in COPD patients.

• Dietary fiber intake was positively correlated with FEV1 (r = 0.41, P < 0.001).
• Dietary fiber intake was positively correlated with DLCO (r = 0.38, P < 0.001).
• Lung function parameters (FEV1, FEV1/FVC, DLCO) were evaluated according to ATS/ERS guidelines.

Low dietary fiber intake was associated with significantly increased odds of COPD after adjusting for confounders.

• Low dietary fiber intake (< 20 g/day) was associated with a 3.2-fold increased odds of COPD (OR = 3.24, 95% CI: 1.86–5.65, P < 0.001).
• The association was assessed using logistic regression analysis adjusted for confounders.
• Causality cannot be established due to the cross-sectional case-control design.