Gut microbiota dysbiosis contributes to the development of chronic obstructive pulmonary disease

Abstract

Background Dysbiosis of the gut microbiome is involved in the pathogenesis of various diseases, but the contribution of gut microbes to the progression of chronic obstructive pulmonary disease (COPD) is still poorly understood. Methods We carried out 16S rRNA gene sequencing and short-chain fatty acid analyses in stool samples from a cohort of 73 healthy controls, 67 patients with COPD of GOLD stages I and II severity, and 32 patients with COPD of GOLD stages III and IV severity. Fecal microbiota from the three groups were then inoculated into recipient mice for a total of 14 times in 28 days to induce pulmonary changes. Furthermore, fecal microbiota from the three groups were inoculated into mice exposed to smoke from biomass fuel to induce COPD-like changes. Results We observed that the gut microbiome of COPD patients varied from that of healthy controls and was characterized by a distinct overall microbial diversity and composition, a Prevotella-dominated gut enterotype and lower levels of short-chain fatty acids. After 28 days of fecal transplantation from COPD patients, recipient mice exhibited elevated lung inflammation. Moreover, when mice were under both fecal transplantation and biomass fuel smoke exposure for a total of 20 weeks, accelerated declines in lung function, severe emphysematous changes, airway remodeling and mucus hypersecretion were observed. Conclusion These data demonstrate that altered gut microbiota in COPD patients is associated with disease progression in mice model.

The treatment of Qibai Pingfei Capsule on chronic obstructive pulmonary disease may be mediated by Th17 / Treg balance and gut-lung axis microbiota

“…Consistent with previous studies, the proportion of Firmicutes in the lung was lower [35], while that was higher in the gut [11] in the model group than in the control group. Nevertheless, interestingly, the proportion of Proteobacteria in the gut and lung was lower in the model group than that of the control group in our study [11,36]. Many common human pathogens belong to the Proteobacteria, and their proportions were negatively correlated with the FEV1/FVC value [35].…”

“…Bacteroidetes, butyrate-producing bacteria [31], are essential for the degradation of complex carbohydrate biomes [32]. Bacteroidetes of intestinal and pulmonary microbiota were lower in the model group than in the control group in this experiment, consistent with the previous facts [11,33]. Firmicutes, Gram-positive bacteria, can produce more harvestable energy than Bacteroidetes.…”

“…When the relative abundance of Firmicutes increases and Bacteroidetes decreases, the difference in terms of energy harvesting can promote metabolic diseases [34]. Consistent with previous studies, the proportion of Firmicutes in the lung was lower [35], while that was higher in the gut [11] in the model group than in the control group. Nevertheless, interestingly, the proportion of Proteobacteria in the gut and lung was lower in the model group than that of the control group in our study [11,36].…”

“…The characteristic gut microbiota of obese patients with Polycystic ovary syndrome is Coprococcus_2 [92]. Some species of Prevotella have inflammatory properties [93] and maybe involved in COPD [11]. High content of Prevotella in the airways has been correlated with enhanced concentrations of IL-17, among other cytokines, and Th17 cells [94].…”

“…Gut microbiota dysbiosis plays a causal effect influencing the severity of cigarette smoke-induced COPD pathogenesis [10]. Faecal microbiota transplantation experiments further indicate that altered gut microbiota in COPD patients accelerated COPD progression in mice [11]. Lungs were once considered to be a sterile environment [12].…”