Objective:

2

To explore the effects and mechanism of Chinese medicine Liujunzi Decoction (LJZD) on regulating microbial flora in mice with asthma flora disorder.

Methods:

2

Thirty BALB/c female mice were divided into control

model

LJZD [3.5 g/(kg•d)

by gavage

]

dexamethasone [DXMS

0.7 mg/(kg•d)

intraperitoneal injection

]

and

Clostridium butyricum

[CB

230 mg/(kg•d)

by gavage

]

groups according to a random number table

6 mice in each group. The asthma flora disorder mice model was induced with ovalbumin (OVA). Lung and gut lesions were analyzed by hematoxylin-eosin (HE) and periodic acid-Schiff (PAS) stainings. The secretory immunoglobulin A (sIgA) protein expression in lung and gut tissues was detected by Western blot. Flow cytometry was used to detect the relative counts of GATA binding protein 3 (GATA3)/type 2 innate lymphoid cells (ILC2) in lung and gut. The levels of inflammatory factors in lung and gut tissues were detected by enzyme-linked immunosorbent assay (ELISA). Chao1 and Shannon index were used to compare microbial abundance and diversity in alveolar lavage fluid and cecal contents. The similarity or difference in the composition of mice microbial communities was analyzed through cluster analysis. The serum short-chain fatty acids (SCFAs) content was detected by ultra performance liquid chromatograph mass spectrometer (LC-MS)/MS.

Results:

2

The asthma flora disorder model mice showed obvious asthma-related symptoms

but LJZD treatment effectively alleviated these symptoms. LJZD restored alveolar wall thickening

airway inflammatory cell infiltration

gut tissue structure destru

ction

and inflammatory cell infiltration in asthma flora disorder mice. LJZD downregulated the sIgA protein expression in mice (

P

<

0.05). Moreover

LJZD decreased the activation of GATA3/ILC2s in lung and gut tissue (

P

<

0.01)

and reduced the levels of interleukin (IL)-5

IL-33

IL-25

IL-9 and IL-13 (

P

<

0.01). LJZD treatment returned the abundance of microbial species and the microbial community structure of alveolar lavage fluid and cecal content in asthma flora disorder mice to the normal state. The SCFAs content and body metabolism were also improved.

Conclusion:

2

LJZD exerted anti-asthmatic effects by improving the microbial balance of lung–gut axis and affecting systemic metabolism

consequently regulating the GATA3/ILC2s axis to impact the lung inflammatory response.