Oral microbial communities in children, caregivers, and associations with salivary biomeasures and environmental tobacco smoke exposure

Authors

Jason A. Rothman, University of California, Irvine
Jenna L. Riis, University of California, Irvine
Katrina R. Hamilton, University of California, Irvine, Johns Hopkins University School of Medicine
Clancy Blair, New York University
Douglas A. Granger, University of California, Irvine, Johns Hopkins University School of Nursing, Johns Hopkins University School of Medicine, University of Nebraska
Katrine Katrine Whiteson, University of California, Irvine

Date of this Version

6-20-2023

Citation

July/August Volume 8 Issue 4. 10.1128/msystems.00036-23

Comments

Open access.

Abstract

Human oral microbial communities are diverse, with implications for oral and systemic health. Oral microbial communities change over time; thus, it is important to understand how healthy versus dysbiotic oral microbiomes differ, especially within and between families. There is also a need to understand how the oral microbiome composition is changed within an individual including by factors such as environmental tobacco smoke (ETS) exposure, metabolic regulation, inflammation, and antioxidant potential. Using archived saliva samples collected from caregivers and children during a 90-month follow-up assessment in a longitudinal study of child development in the context of rural poverty, we used 16S rRNA gene sequencing to determine the salivary microbiome. A total of 724 saliva samples were available, 448 of which were from caregiver/child dyads, an additional 70 from children and 206 from adults. We compared children’s and caregivers’ oral microbiomes, performed “stomatotype” analyses, and examined microbial relations with concentrations of salivary markers associated with ETS exposure, metabolic regulation, inflammation, and antioxidant potential (i.e., salivary cotinine, adiponectin, C-reactive protein, and uric acid) assayed from the same biospecimens. Our results indicate that children and caregivers share much of their oral microbiome diversity, but there are distinct differences. Microbiomes from intrafamily individuals are more similar than microbiomes from nonfamily individuals, with child/caregiver dyad explaining 52% of overall microbial variation. Notably, children harbor fewer potential pathogens than caregivers, and participants’ microbiomes clustered into two groups, with major differences being driven by Streptococcus spp. Differences in salivary microbiome composition associated with ETS exposure, and taxa associated with salivary analytes representing potential associations between antioxidant potential, metabolic regulation, and the oral microbiome.