Probiotics in COPD: Effects on Symptoms, Lung Function, and Inflammation

Chronic obstructive pulmonary disease (COPD) is a progressive respiratory condition characterized by persistent symptoms such as shortness of breath, chronic cough, sputum production, and periods of acute worsening. It is also associated with ongoing systemic inflammation, which contributes to symptom severity, impaired lung function, and increased risk of exacerbations. Emerging evidence suggests that the gut-lung axis may play a significant role in this inflammatory process. Probiotics, which help restore a healthy microbial balance and support gut barrier integrity, have been proposed as a potential strategy to modulate inflammation and respiratory symptoms. Several studies have suggested that probiotics may reduce respiratory symptoms, improve lung function and lower systemic inflammation in people with COPD. This randomized study is designed to evaluate whether a probiotic supplement (Saccharomyces boulardii, Lactobacillus plantarum LP 6596, and Lactobacillus plantarum HEAL9) can improve shortness of breath, overall symptom burden, lung function, and selected inflammatory markers in adults with stable COPD compared with placebo. Participants will be recruited from multiple clinical centers and will continue their usual COPD therapy throughout the study period. A total of 60 adult participants with a confirmed diagnosis of COPD, stable disease and baseline dyspnea of mMRC (modified Medical Research Council) ≥ 1 will be randomized to receive either a probiotic supplement or placebo for 16 weeks. They will take either the probiotic supplement or placebo 2 capsules once daily for 16 weeks and will be examined at three clinic visits for symptom questionnaires- mMRC scale of dyspnea, CAT (COPD Assessment Test) and Bristol Stool Scale, blood sampling, and spirometry testing. Between clinic visits, participants will have regular telephone checks every 4 weeks to assess symptoms, adherence to the study product and possible side effects. This trial aims to provide a more comprehensive understanding of how probiotic supplementation may influence dyspnea, quality of life, inflammatory activity, and respiratory function in COPD.