The Relationship Between Lower Respiratory Tract Microbiome and Allergic Respiratory Tract Diseases in Children

Jinghua Cui,Qun Zhang,Han Liu,Yanling Feng,Shaoli Li,Chao Yan,Xianghui Xie,Yuanyuan Zhang,Jing Yuan,Hanqing Zhao,Xuemei Sun,Zhen Chen,Guanhua Xue

doi:10.3389/fmicb.2021.630345

Abstract

Similar to those in the upper respiratory tract, there are microbes present in the healthy human lower respiratory tract (LRT), including the lungs and bronchus. To evaluate the relationship between LRT microbiome and allergic respiratory diseases in children, we enrolled 68 children who underwent bronchoscopy from January 2018 to December 2018 in the affiliated hospital of the Capital Institute of Pediatrics. Using the total IgE (TIgE) values, children were divided into two groups: allergy sensitivity (AS) group and non-allergy sensitivity (NAS) group. Nucleic acid was extracted from samples of bronchoalveolar lavage fluid (BALF) from the two groups of children taken during bronchoscopy treatment and the 16S rDNA gene was sequenced and analyzed. The results showed that Haemophilus, Moraxella, Streptococcus, Prevotella, Neisseria, and Rothia were detected in all patients. There was a statistically significant difference in the composition and distribution of microbiota between the AS and NAS groups (p < 0.01). Analysis of the correlation of clinical indices and microbiome showed that TIgE was positively correlated with Bacteroidetes and negatively correlated with Streptococcus. Absolute lymphocyte count showed a relationship with Streptococcus, and the absolute neutrophil count or percentage of neutrophils showed a relationship with Cardiobacterium. The LRT microbiome functioned similarly to the intestinal microbiome. That is, the decrease in microbial diversity and the change in composition could lead to an increase in allergic symptoms. The microbiome of the LRT in children, especially that of Bacteriodetes and Streptococcus, showed a correlation with respiratory allergic diseases.

Highlights

At present, the prevalence rate of allergic rhinitis in mainland China is 4–38% (Zhang and Zhang, 2014)
The non-allergy sensitivity (NAS) group had presented with a total immunoglobulin E (IgE) ≤ 60 IU/mL and a diagnosis pneumonia or bronchopneumonia, without allergic symptoms
Compared to the control NAS group using mean propotion between groups, we examined the difference in the relative caculation, the LRT microbiome in the children of the allergy sensitivity (AS) group abundance of the bacteria between the cohorts at the genus had lower levels of Streptococcus, Lactobacillus, Anoxybacillus, FIGURE 2 | A principal coordinate analysis (PCA) plot based on 16S rDNA sequencing of 64 lower respiratory tract (LRT) samples

Summary

Introduction

The prevalence rate of allergic rhinitis in mainland China is 4–38% (Zhang and Zhang, 2014). During the past few decades, the prevalence of allergic respiratory diseases in children, especially asthma caused by allergies, has been increasing year by year in China (Sha et al, 2016) This rapid increase in atopic diseases can be explained by the “hygiene hypothesis,” which suggests that low infection rates in developed countries lead to inappropriate immune activation of immunoglobulin E (IgE) against the common environment and autoantigens (Anvari et al, 2019). This hypothesis may account for the recent increase observed in food allergies, especially among children (Pascal et al, 2018). Previous reports have demonstrated a quantitative relationship between serum IgE and various allergic diseases (Testa et al, 2020)

Methods

Results

Conclusion