Clinical Research Trends of Gut Microbiome for Respiratory Diseases

Abstract

Objectives: This study aimed to review the clinical research of the gut microbiome for respiratory diseases to assist the design of trials for respiratory diseases by regulating the gut microbiome with herbal medicine later. Methods: We searched three international databases (PubMed, CENTRAL and EMBASE) to investigate randomized controlled trials (RCTs) of the gut microbiome for respiratory diseases. The selected trials were analyzed by study design, subject diseases, inclusion/exclusion criteria, sample size, study period, intervention group, control group, outcome measures, and study results. Results: A total of 25 studies were included and published from 1994 to 2021 mostly in Europe and Asia. Subject diseases were many in the order of respiratory tract infection, cystic fibrosis, allergy, and so on. As outcome measures, the gut microbiome in a fecal sample was analyzed by 16S rRNA sequencing analysis method, and symptom assessment tools related each disease were used. Major intervention drugs were probiotics and the results were mostly improved in the composition and diversity of the gut microbiome. Conclusion: Clinical studies of the gut microbiome for respiratory diseases have confirmed various effects and this review provides basic data for a well-designed clinical study for respiratory diseases by regulating the gut microbiome with herbal medicine.