Therapeutic and prophylactic effects of Qipian on COPD in mice: the role of lung and gut microbiota

Abstract

The objective of this study was to investigate the therapeutic and prophylactic effects of the mixed extract of Staphylococcus and Neisseria tablets (Qipian) on chronic obstructive pulmonary disease (COPD) in mice and its relationship with lung and gut microbiota. C57BL/6 mice were divided into two models (prophylactic versus therapeutic administration). In the model of prophylactic administration, the mice were exposed to cigarette smoke (CS) for 16 weeks and divided into CS+Qipian group, CS+OM-85 group, and CS control group. Compared to the CS control group, mice in both CS+Qipian and CS+OM-85 groups had improved lung function, reduced pulmonary bullae and inflammatory cell infiltration, reduced collagen deposition around the bronchi, and decreased levels of inflammatory cytokines in the lung tissue. Qipian and OM-85 significantly increased the diversity of gut and lung microbiota and the abundance of Bacteroidetes, Bacteroidales, and Lactobacillus, as well as inhibited the toll-like receptor 4 (TLR4)/nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB) pathway. There were no significant differences in the above parameters between the CS+OM-85 group and the CS+Qipian group. In the therapeutic administration model, the mice were exposed to CS for 24 weeks, and the results were consistent with those of the prophylactic administration model. Qipian administration has both preventive and therapeutic effects on COPD possibly by regulating the microbiota dysbiosis through the gut-lung axis, inhibiting the activation of the TLR4/NF-κB pathway, reducing inflammation, and improving lung function.IMPORTANCEGut and lung microbiota are associated with the development and progression of chronic obstructive pulmonary disease (COPD). Qipian treatment significantly increased the diversity of gut and lung microbiota and the abundance of Bacteroidetes, Bacteroidales, and Lactobacillus. In addition, the toll-like receptor 4/nuclear factor kappa-light-chain enhancer of activated B cells pathway mediated by the gut-lung axis may play an essential role in preventing and treating the pathogenesis of COPD, which allows for reduced inflammation and improvement of lung function.

Keywords: Staphylococcus and Neisseria tablet; chronic obstructive pulmonary disease; gut microbiota; lung microbiota; toll-like receptor 4.

Fig 1

Schematic diagram of the experimental setup.

Fig 2

Weight changes in the two models. (A) Prophylactic administration model. (B) Therapeutic administration model.

Fig 3

CS-induced exposure in mice resulted in alteration of respiratory parameters. (A–H) Lung function indexes of mice in the model of prophylactic administration. (I–P) Lung function indexes of mice in the model of therapeutic administration. (A) Te = expiration time, (B) EF50 = 50% expiratory flow rate, (C) f = respiratory rate, (D) PEF = maximum expiratory volume, (E) PENH = forced breath gap, (F) Rpef = time-to-peak expiratory ratio, (G) TV = tidal vol, (H) MV = expiratory vol per minute, (I) forced vital capacity (FVC), (J) forced expiratory volume at 25 ms (FEV25ms), (K) forced expiratory volume at 50 ms (FEV50ms), (L) forced expiratory volume at 75 ms (FEV75ms), (M) the ratio of forced expiratory volume at 25 ms to total expiratory volume (FEV25ms/FVC), (N) FEV50ms/FVC, (O) FEV75ms/FVC, and (P) peak inspiratory flow rate (PIF). *P < 0.05, **P < 0.01, and ***P < 0.001.

Fig 4

Pathological changes and expression of inflammatory cytokines in lung tissues. (A) HE staining. (B) PAS staining. (C) MT staining. (D) α-SMA immunohistochemistry. (E, G) Mean alveolar number. (F, H) Mean linear intercept. (I–K) Expression levels of TNF-α, IL-17, and IL-13 in the lung tissues in the model of prophylactic administration. (L–N) Expression levels of TNF-α, IL-17, and IL-13 in the lung tissues in the model of therapeutic administration. Data were expressed as mean ± standard error. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001.

Fig 5

Gut microbiota analysis. (A, B) Chao1 and Shannon indexes in the model of prophylactic administration. (C, D) Chao1 and Shannon indexes in the model of therapeutic administration. (E, F) Principal coordinates analysis of gut microbiota in the models of prophylactic and therapeutic administration. (G, H) Histogram of gut microbiota distribution at the phylum level in the models of prophylactic and therapeutic administration. (I–K) LEfSe analysis in the model of prophylactic administration. (L) LEfSe analysis in the model of therapeutic administration. *P < 0.05.

Fig 6

Lung microbiota analysis. (A, B) Chao1 and Shannon indexes in the model of prophylactic administration. (C, D) Chao1 and Shannon indexes in the model of therapeutic administration. (E, F) Principal coordinates analysis of lung microbiota in the models of prophylactic and therapeutic administration. (G, H) Histogram of airway microbiota distribution at the phylum level in the models of prophylactic and therapeutic administration. (I–K) LEfSe analysis in the model of prophylactic administration. (L) LEfSe analysis in the model of therapeutic administration. *P < 0.05.

Fig 7

Correlations of microbiota and inflammatory cytokines. (A) The correlation between gut microbiota and inflammatory cytokines in lung tissues of mice in the prophylactic administration model. (B) The correlation between gut microbiota and inflammatory cytokines in lung tissues of mice in the therapeutic administration model. (C) The correlation between lung microbiota and inflammatory cytokines in lung tissues of mice in the prophylactic administration model. (D) The correlation between lung microbiota and inflammatory cytokines in lung tissues of mice in the therapeutic administration model.

Fig 8

Effects of Qipian on the TLR4/NF-κB signaling pathway. (A, B) Western blot was performed to detect the expression of TLR4, p-NFkBp65, and NF-κBp65 in the model of prophylactic administration. (C, D) Western blot was performed to detect the expression of TLR4, p-NF-κBp65, and NF-κBp65 in the model of therapeutic administration. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001.