Metagenomic analysis reveals associations between salivary microbiota and body composition in early childhood

Abstract

Several studies have shown that body mass index is strongly associated with differences in gut microbiota, but the relationship between body weight and oral microbiota is less clear especially in young children. We aimed to evaluate if there is an association between child growth and the saliva microbiome. We hypothesized that associations between growth and the saliva microbiome would be moderate, similarly to the association between growth and the gut microbiome. For 236 toddlers participating in the New Hampshire Birth Cohort Study, we characterized the association between multiple longitudinal anthropometric measures of body height, body weight and body mass. Body Mass Index (BMI) z-scores were calculated, and dual-energy x-ray absorptiometry (DXA) was used to estimate body composition. Shotgun metagenomic sequencing of saliva samples was performed to taxonomically and functionally profile the oral microbiome. We found that within-sample diversity was inversely related to body mass measurements while community composition was not associated. Although the magnitude of associations were small, some taxa were consistently associated with growth and modified by sex. Certain taxa were associated with decreased weight or growth (including Actinomyces odontolyticus and Prevotella melaninogenica) or increased growth (such as Streptococcus mitis and Corynebacterium matruchotii) across anthropometric measures. Further exploration of the functional significance of this relationship will enhance our understanding of the intersection between weight gain, microbiota, and energy metabolism and the potential role of these relationships on the onset of obesity-associated diseases in later life.

Characterization of the oral and gut microbiome in children with obesity aged 3 to 5 years

“…Furthermore, certain taxa, such as Actinomyces odontolyticus and Prevotella melaninogenica, were associated with decreased weight or growth, and Streptococcus mitis and Corynebacterium matruchotii were associated with increased growth across anthropometric parameters. Coker et al (Coker et al, 2022) also reported that both rapid weight gain between 0 and 2 years of age and weight-to-length ratio were associated with BMI at 3-4 years of age among both males and females, a finding that was in accordance with those of a study of 2-year-old children by Craig et al (Craig et al, 2018), who reported that children who gain weight rapidly before the age of 2 years are more likely to be obese later in childhood and adulthood. The oral microbiota is thought to mediate obesity signals even earlier than the gut microbiota.…”

“…The oral microbiota of young children was extensively studied by Coker et al (2022) . In that study, analysis of the community composition of the salivary microbiota by growth status indicated that the majority of the saliva microbiota consisted of members of the Firmicutes, followed by Proteobacteria, Actinobacteria, and Bacteroidetes.…”

“…Coker et al. ( Coker et al., 2022 ) also reported that both rapid weight gain between 0 and 2 years of age and weight-to-length ratio were associated with BMI at 3-4 years of age among both males and females, a finding that was in accordance with those of a study of 2-year-old children by Craig et al. ( Craig et al., 2018 ), who reported that children who gain weight rapidly before the age of 2 years are more likely to be obese later in childhood and adulthood.…”

The Relationship between Obesity and Childhood Dental Caries in the United States

“…Regarding potential explanations for the obesity-caries relationship, it has been reported that obesity can lead to changes in the oral microflora and salivary properties, which in turn might predispose children to develop dental caries [ 13 , 14 , 15 ]. This explanation implies that dental caries is a consequence of obesity.…”

Associations of central obesity and habitual food consumption with saliva microbiota and its enzymatic profiles – a pilot study in Finnish children

“…Furthermore, as 1.5 liters of saliva is ingested daily, its role as an enhancer of gut colonization has also been proposed ( Wade, 2021 ). Some studies have investigated saliva microbiota in overweight/obese children ( Raju et al, 2019 ; Coker et al, 2022 ), but their results have been discordant with each other possibly due to differences in the study design, age range, and methodology. Moreover, none of these studies have considered central obesity that is mirrored by waist circumference or waist–height ratio (WHtR).…”