AUTHOR=Huang Xin , Chen Xuehui , Gong Xu , Xu Ying , Xu Zhifei , Gao Xuemei 

TITLE=Characteristics of salivary microbiota in children with obstructive sleep apnea: A prospective study with polysomnography

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.945284

DOI=10.3389/fcimb.2022.945284

ISSN=2235-2988

ABSTRACT=<sec><title>Objectives</title><p>The present study aimed to investigate the characteristics of salivary microbiota of children with obstructive sleep apnea (OSA) and to assess longitudinal alterations in salivary microbiota before and after adenotonsillectomy.</p></sec><sec><title>Methods</title><p>A set of cross-sectional samples consisted of 36 OSA children (17 boys and 19 girls, 7.47 ± 2.24 years old) and 22 controls (9 boys and 13 girls, 7.55 ± 2.48 years old) were included in the study, among which eight OSA children (five boys and three girls, 8.8 ± 2.0 years old) who underwent treatment of adenotonsillectomy were followed up after 1 year. Saliva samples were collected, and microbial profiles were analyzed by bioinformatics analysis based on 16S rRNA sequencing.</p></sec><sec><title>Results</title><p>In cross-sectional samples, the OSA group had higher α-diversity as estimated by Chao1, Shannon, Simpson, Pielou_e, and observed species as compared with the control group (<italic>p</italic> &lt; 0.05). β-Diversity based on the Bray–Curtis dissimilarities (<italic>p</italic> = 0.004) and Jaccard distances (<italic>p</italic> = 0.001) revealed a significant separation between the OSA group and control group. Nested cross-validated random forest classifier identified the 10 most important genera (<italic>Lactobacillus</italic>, <italic>Escherichia</italic>, <italic>Bifidobacterium</italic>, <italic>Capnocytophaga</italic>, <italic>Bacteroidetes_[G-7]</italic>, <italic>Parvimonas</italic>, <italic>Bacteroides</italic>, <italic>Klebsiella</italic>, <italic>Lautropia</italic>, and <italic>Prevotella</italic>) that could differentiate OSA children from controls with an area under the curve (AUC) of 0.94. Linear discriminant analysis effect size (LEfSe) analysis revealed a significantly higher abundance of genera such as <italic>Prevotella</italic> (<italic>p</italic> = 0.027), <italic>Actinomyces</italic> (<italic>p</italic> = 0.015), <italic>Bifidobacterium</italic> (<italic>p</italic> &lt; 0.001), <italic>Escherichia</italic> (<italic>p</italic> &lt; 0.001), and <italic>Lactobacillus</italic> (<italic>p</italic> &lt; 0.001) in the OSA group, among which <italic>Prevotella</italic> was further corroborated in longitudinal samples. <italic>Prevotella sp_HMT_396</italic> was found to be significantly enriched in the OSA group (<italic>p</italic> = 0.02) with significantly higher levels as OSA severity increased (<italic>p</italic> = 0.014), and it had a lower abundance in the post-treatment group (<italic>p</italic> = 0.003) with a decline in each OSA child 1 year after adenotonsillectomy.</p></sec><sec><title>Conclusions</title><p>A significantly higher microbial diversity and a significant difference in microbial composition and abundance were identified in salivary microbiota of OSA children compared with controls. Meanwhile, some characteristic genera (<italic>Prevotella</italic>, <italic>Actinomyces</italic>, <italic>Lactobacillus</italic>, <italic>Escherichia</italic>, and <italic>Bifidobacterium</italic>) were found in OSA children, among which the relationship between <italic>Prevotella</italic> spp. and OSA is worth further studies.</p></sec>