This study aims to investigate various aspects of patients with chronic respiratory diseases undergoing pulmonary rehabilitation supplemented with probiotics. The focus will be on clinical physiological responses, functional performance, respiratory status assessments, nutritional status evaluations, body composition analyses, and biochemical blood parameters, with a primary emphasis on the anti-inflammatory response.

Background： Patients with chronic obstructive pulmonary disease (COPD) often suffer from malnutrition and weight loss, which negatively impact mortality rates. Research indicates that insufficient intake of fiber, vitamins, and folic acid is associated with airflow limitation in COPD. Malnutrition affects lung function and muscle strength, leading to difficulty in breathing and reduced exercise tolerance. Nutritional support interventions, such as probiotics, are valuable in improving the nutritional status, lung function, and pulmonary rehabilitation in COPD patients.

Study Design： This is a one-year, single-center, prospective randomized controlled trial.

Methods： This study is a randomized controlled trial targeting COPD patients undergoing pulmonary rehabilitation. The plan is to recruit 60 participants, randomly assigned to either the probiotic intervention group or the conventional pulmonary rehabilitation group. The study includes physiological parameters, functional tests, questionnaires, and blood biochemical analyses. Data will be analyzed using SPSS, with statistical significance set at p < 0.05.

Effect： The trial expects that COPD patients receiving probiotic supplementation will achieve significant muscle gain and fat loss, reduce inflammation, and exhibit changes in body composition and functional performance.

Key words： Chronic obstructive pulmonary disease; probiotics; nutritional supplementation; inflammation markers; body composition

Inclusion Criteria:

• Willing to sign a written informed consent form.
• Diagnosed with pre-COPD or COPD stage I-IV according to the 2023 GOLD guidelines.
• Undergoing pulmonary rehabilitation therapy for more than three months.

Exclusion Criteria:

• Under 18 years old.
• Diagnosed with neuromuscular diseases.
• Experienced respiratory disease exacerbation requiring emergency care or hospitalization in the past three months.
• Unable to cooperate with cardiopulmonary exercise testing.
• Has other diseases or behavioral restrictions preventing participation in exercise training for over one year.
• Assessed by a physician to have severe malnutrition or a significantly low BMI.