The Composition and Functional Capacities of Saliva Microbiota Differ Between Children With Low and High Sweet Treat Consumption

Abstract

Excess sugar consumption—common in youth—is associated with poor health. Evidence on the relationship between sugar consumption and the oral microbiome, however, remains scarce and inconclusive. We explored whether the diversity, composition, and functional capacities of saliva microbiota differ based on the consumption of select sugary foods and drinks (“sweet treats”). Using 16S rRNA gene sequencing, we characterized saliva microbiota from 11 to 13-year-old children who participated in the Finnish Health in Teens (Fin-HIT) cohort study. The sample comprised children in the lowest (n = 227) and highest (n = 226) tertiles of sweet treat consumption. We compared differences in the alpha diversity (Shannon, inverse Simpson, and Chao1 indices), beta diversity (principal coordinates analysis based on Bray–Curtis dissimilarity), and abundance (differentially abundant operational taxonomic units (OTUs) at the genus level) between these low and high consumption groups. We performed PICRUSt2 to predict the metabolic pathways of microbial communities. No differences emerged in the alpha diversity between low and high sweet treat consumption, whereas the beta diversity differed between groups (p = 0.001). The abundance of several genera such as Streptococcus, Prevotella, Veillonella, and Selenomonas was higher in the high consumption group compared with the low consumption group following false discovery rate correction (p < 0.05). Children with high sweet treat consumption exhibited higher proportions of nitrate reduction IV and gondoate biosynthesis pathways compared with the low consumption group (p < 0.05). To conclude, sweet treat consumption shapes saliva microbiota. Children who consume a high level of sweet treats exhibited different compositions and metabolic pathways compared with children who consume low levels of sweet treats. Our findings reveal novel insights into the relationship between sugary diets and oral microbiota.

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

“…It also contributed to the most abundant nitrate reduction pathway through nitrate reductase. These findings resemble our recent results in another Fin-HIT sample employing 16S profiling on saliva microbiota; that study also highlighted the nitrate reduction pathway in frequent sugar consumers ( Lommi et al, 2022 ). The pathway converts nitrate to nitrite, allowing further metabolism to nitric oxide ( Rosier et al, 2020 ).…”

“…In addition, the role of diet in oral microbiota has been scarcely studied in children. For example, frequent sugar consumption appears to play a role in the composition and functionality of the saliva microbiota ( Lommi et al, 2022 ) but the associations between diet and enzymatic pathways of saliva microbial communities have so far not been examined.…”

Does high sugar intake really alter the oral microbiota?: A systematic review

“…The functional differences found between microbiomes associated with low and high sugar consumption may signify adaptations of the microbiome to environmental changes (enrichment of acidogenic and acid‐tolerant species). This adaptation also involves mechanisms to counteract the pH reduction resulting from sugar consumption or the shift to anaerobic metabolism (Lommi et al, 2022 ; Wang et al, 2019 ). The activation of pathways associated with sugar metabolism indicates high metabolic activity (Chen et al, 2021 ).…”

Pre-Diagnostic Saliva Microbiota of School-Aged Children Who Developed Type 1 Diabetes or Inflammatory Bowel Diseases

“…Saliva microbiota composition may also be influenced by oral hygiene and health, stages of dentition, and dietary patterns-especially by the consumption of sugary products [25]. While the dietary patterns and sugary product consumption of children in the Fin-HIT cohort who developed autoimmune diseases have been reported to be similar to those of those who did not develop these diseases [26], we lacked detailed information on the children's overall oral health as a potential confounder.…”