Objective

2

To observe the effect of electroacupuncture (EA) on the intestinal flora in rats with chronic obstructive pulmonary disease (COPD) and explore its possible mechanism based on the gut-lung axis theory.

Methods

2

A total of 30 male SD rats of SPF grade were randomly divided into a normal control (NC) group

a model group and an EA group

10 rats in each one. In the model group and the EA group

COPD model was established by intratracheal instillation of lipopolysaccharide combined with cigarette fumigation. In the EA group

EA was applied at bilateral "Feishu" (BL13) and "Zusanli" (ST36)

with disperse-dense waves

in frequency of 4 Hz/20 Hz

current of 1-3 mA

20 min a time

once a day for 14 days continuously. Before and after modeling

as well as after intervention

body weight was observed; after intervention

the lung function indexes (forced expiratory volume in 0.1 second [FEV

0.1

]

FEV

0.1

/forced vital capacity [FVC

]

%

forced expiratory volume in 0.3 second [FEV

0.3

]

and FEV

0.3

/FVC%) were measured

serum levels of inflammatory factors (tumor necrosis factor-α[TNF-α

]

interleukin-6

[IL-6

]

interleukin-1β[IL-1β

]

and interleukin-10

[IL-10

]

) were detected by ELISA

histopathology of lung and colon tissues was observed by HE staining

the intestinal flora were analyzed by 16S rRNA

and the correlations between lung function and intestinal flora were analyzed.

Results

2

Compared with the NC group

in the COPD group

the body weight and lung function indexes were reduced (

P

<

0.01); the lung and colon tissues were damaged

the mean linear intercept (MLI) of alveolus and inflammatory cell numbers of 100 μm

2

in lung tissue were increased (

P

<

0.01); the serum levels of TNF-α

IL-6 and IL-1β were increased (

P

<

0.01

P

<

0.05)

and the serum level of IL-10 was decreased (

P

<

0.01); α-d

iversity indexes of intestinal flora were increased (

P

<

0.01); the relative abundance of

Bacteroidetes

Proteobacteria

and

Oscillospira

Bacteroides

Coprococcus

was increased (

P

<

0.01)

the relative abundance of

Firmicutes

Actinobacteria

Tenericutes

TM7 and

Lactobacillus

Allobaculum

Bifidobacterium

YRC22 was decreased (

P

<

0.01

P

<

0.05); 31 different expressed metabolic pathways were identified between the two groups. Compared with the COPD group

in the EA group

the body weight and lung function indexes were increased (

P

<

0.01); the damage of lung and colon tissues was improved

the MLI of alveolus was decreased (

P

<

0.05); the serum levels of TNF-α

IL-6 and IL-1β were decreased (

P

<

0.05)

and the serum level of IL-10 was increased (

P

<

0.05); α-diversity indexes of intestinal flora were decreased (

P

<

0.01); the relative abundance of

Bacteroidetes

Proteobacteria

and

Oscillospira

Bacteroides

Coprococcus

was decreased (

P

<

0.01

P

<

0.05)

the relative abundance of

Firmicutes

Actinobacteria

Tenericutes

TM7 and

Lactobacillus

Allobaculum

Bifidobacterium

YRC22 was increased (

P

<

0.01); 35 different expressed metabolic pathways were identified between the two groups. The lung function was positive related with

Actinobacteria

Tenericutes

TM7 and YRC22

and was negative related with

Bacteroidetes

Proteobacteria

and

Oscillospira

Bacteroides

Coprococcus

.

Conclusion

2

EA may ameliorate lung function and tissue injury of COPD by regulating intestinal flora dysbiosis and inflammatory response

suggesting an anti-inflammatory effect mediated via "gut-lung" axis.