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

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.

Temporal Dynamics of the Nasopharyngeal Microbiome and its Relationship with Childhood Asthma Exacerbation

“…Anoxybacillus was one of the most abundant airborne thermophilic bacterial genera in China ( 31 ) that contaminated processed food products, which were not initially considered human colonizers ( 32 ). However, a recent study reported that Anoxybacillus enrichment in the lower respiratory tract might suppress allergies in Chinese children ( 33 ). We revealed that this genus decreased with time independent of AE, suggesting Anoxybacillus to be a transient colonizer of NPM with a potentially protective role in Asian asthmatic children.…”

Immunologic, genetic, and ecological interplay of factors involved in allergic diseases

“…Additionally, pharyngeal colonization of Haemophilus sp. and Streptococcus sp., together with the upper respiratory tract pathogen Moraxella sp., was identified as a risk factor for acute and aggravated allergic asthma episodes among children ( 99 ). Finally, the impact of synergistic infections with respiratory pathogens, such as the influenza A virus and Streptococcus pneumoniae was also implicated to interact with factors associated allergic inflammation to Aspergillus fumigatus .…”

Nasal Microbiome Change During and After Exacerbation in Asthmatic Children

“…Although several studies have investigated airway or gut microbiota in childhood asthma (Bisgaard et al, 2007;Arrieta et al, 2015;Cui et al, 2015;Teo et al, 2015Teo et al, , 2018Bomar et al, 2018), limited studies examined nasal microbiota in school children and adolescents (Kloepfer et al, 2014;Perez-Losada et al, 2017;McCauley et al, 2019;Zhou et al, 2019), and only two focused on acute exacerbation (AE) (McCauley et al, 2019;Zhou et al, 2019). AE represents a specific window of time of an agitated immune system.…”