Abstract
Aims: The 16srRNA gene sequencing method was employed to examine the alterations in the nasopharyngeal and pulmonary microbiome of asthmatic mice following CpG-ODN treatment, thereby offering a novel approach to the diagnosis and treatment of asthma.
Methods: Ovalbumin (OVA) sensitized mice were used to establish allergic asthma model by weekly intraperitoneal injection of OVA for three consecutive weeks, and CpG-ODN was inhaled before inducing acute asthma on the 21st and 22nd day. Subsequently, 16srRNA gene sequencing technology was performed to analyse the alterations in the nasopharyngeal and pulmonary microbiome of OVA-sensitized asthma-induced mice following CpG-ODN treatment.
Results: CpG-ODN can significantly ameliorate pathological alterations such as inflammatory cell infiltration in the respiratory tract and clinical manifestations of OVA-induced allergic asthma. The treatment of CpG-ODN exhibits distinct effects on lung tissue and nasopharyngeal tissue, potentially enhancing the abundance and variety of microbiome in the latter. At the phylum level, OVA-induced asthma resulted in an increase in the proportion of Proteobacteria in lung and nasopharyngeal tissues, accompanied by a decline in the proportion of Actinobacteria. Subsequent intervention using CpG-ODN successfully restored the proportions of Proteobacteria and Actinobacteria to near-control levels. At the order level, the proportion of Bacteroidales, Clostridiales, and Actinomycetales in lung tissue diminished following OVA sensitization. Subsequent to CpG-ODN treatment, the proportion of the above three bacterial orders escalated and approximated the proportion of the control group. The proportion of Lactobacillales in nasopharyngeal tissues diminished following OVA sensitization, and it tended to approach the level of the control group after the treatment of CpG-ODN. The microbial diversity of the lung tissue in OVA-induced asthmatic mice exhibits a decline, while the microbial diversity of the nasopharyngeal tissue demonstrates an increase.
Conclusions: The treatment of CpG-ODN has been shown to reverse the alterations in microbiome associated with OVA-induced asthma, thereby promoting a stabilization of the respiratory tract microbiome in OVA-sensitized asthma model mice.