Bacterial salivary microbiome associates with asthma among african american children and young adults

Abstract

Several studies have shown that the airways of asthma patients contain higher diversity of bacteria and are enriched in pathogenic species. However, sampling the airways in children is challenging. Here we aimed to identify differences in the salivary bacterial composition between African Americans children with and without asthma. Saliva samples from 57 asthma cases and 57 healthy controls were analyzed by means of 16S ribosomal RNA amplicon profiling. Measurements of bacterial diversity and genus relative abundance were compared between cases and controls using the nonparametric Wilcoxon test and multivariate regression models. A total of five phyla and a mean of 56 genera were identified. Among them, 15 genera had a relative abundance greater than 1%, being Prevotella, Haemophilus, Streptococcus, and Veillonella the most abundant genera. Differences between cases and controls were found in terms of diversity, as well as in relative abundance for Streptococcus genus (13.0% in cases vs 18.3% in controls; P = .003) and Veillonella genus (11.1% in cases vs 8.0% in controls; P = .002). These differences remained significant after correction for multiple comparisons and when potential confounders were taken into account in logistic regression models. In conclusion, we identified changes in the salivary microbiota associated with asthma among African Americans.

Diversity of Microbial Signatures in Asthmatic Airways

“…Although the majority of studies targeting the salivary microbiome have focused on its relationship with dental diseases, a subset of studies have assessed the relationship between the salivary microbiome and allergic disorders, such as asthma. 25 , 27 In one study, saliva was collected longitudinally at three, six, 12, and 24 months and seven years from children with allergies and healthy counterparts. Allergies, particularly asthma, resulted in alterations in the microbial composition with reduced diversity at the age of seven years, suggesting the presence of an impaired immune response during infancy.…”

“…Espuela‐Ortiz et al examined the salivary microbial composition in 57 African–American children with and without asthma based on 16S RNA gene profiles and detected differences between cases and controls with respect to diversity and relative abundance, with significantly higher frequencies of Streptococcus and Veillonella in the disease group than in the control group. 27 …”

“…25 Espuela-Ortiz et al examined the salivary microbial composition in 57 African-American children with and without asthma based on 16S RNA gene profiles and detected differences between cases and controls with respect to diversity and relative abundance, with significantly higher frequencies of Streptococcus and Veillonella in the disease group than in the control group. 27 Other studies have examined the microbial community in the throat of patients with asthma. Based on 327 throat swabs evaluated by pyrosequencing of the 16S rRNA gene, there was no difference in the oral microbiome between cases and controls.…”

“…3 The term dysbiosis has been used increasingly in the last decade and is the basis for many studies of the interactions between the human microbiome and various inflammatory conditions, with more than 2370 published articles in 2020 alone (265, Asthma related), compared to 34 published work in 2010. (NCBI.com, last accessed January 27,2021).…”

The Genomics and Metagenomics of Asthma Severity (GEMAS) Study: Rationale and Design

“…This approach has been applied to describe the microbial diversity in the airways and the continuity in bacterial communities through the oral cavity, upper airways, and lungs [ 16 , 17 ]. In relation to asthma, the alteration (dysbiosis) of the nasopharyngeal or the salivary microbiome is associated with asthma susceptibility and different phenotypes of severe asthma [ 18 , 19 , 20 ]. Moreover, respiratory pathogens constitute known triggers for asthma exacerbations and are involved in the development of airway inflammation [ 16 , 21 ].…”