Low levels of salivary metals, oral microbiome composition and dental decay

Elyse Davis,Betsy Foxman,Kelly M Bakulski,Jaclyn M Goodrich,Karen E Peterson,Mary L Marazita

doi:10.1038/s41598-020-71495-9

Elyse Davis, Betsy Foxman + Show 4 more

Open Access

https://doi.org/10.1038/s41598-020-71495-9

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Abstract

Salivary microbiome composition can change following exposure to environmental toxicants, e.g., heavy metals. We hypothesized that levels of salivary nutrients and metals would correlate with salivary microbiome composition and be associated with dental decay. Here we assess the salivary concentrations of 5 essential minerals (cobalt, copper, manganese, molybdenum, and zinc), 4 metals with some evidence of normal physiological function (chromium, nickel, tungsten, and vanadium), and 12 with known toxicity (antimony, arsenic, barium, beryllium, cadmium, cesium, lead, mercury, platinum, thallium, tin, and uranium), and their associations with salivary microbiome composition and dental decay in 61 children and adults. 16 metals were detected in 54% of participants; 8 were found in all. Marked differences in salivary bacterial taxa were associated with levels of antimony, arsenic, and mercury, after adjusting for multiple testing. Further, antimony levels were associated with the presence of decayed teeth. Thus, salivary metal levels, even at low concentrations, may impact oral health.

Highlights

Salivary microbiome composition can change following exposure to environmental toxicants, e.g., heavy metals
As it is clear that the microbiome at all body sites responds to environmental stressors such as pathogens and environmental chemicals, it is critical to understand the implications of metal exposures on the structure, composition, and function of the oral microbiome, taking into account whether the metal is exclusively toxic, an essential mineral, or has some physiological functions
E.g., lead or cadmium, are measured in blood or urine the resulting levels can be compared to guidelines for concentrations of c oncern[6]; no guidelines exist for salivary metal levels

Summary

Introduction

Salivary microbiome composition can change following exposure to environmental toxicants, e.g., heavy metals. We assess the salivary concentrations of 5 essential minerals (cobalt, copper, manganese, molybdenum, and zinc), 4 metals with some evidence of normal physiological function (chromium, nickel, tungsten, and vanadium), and 12 with known toxicity (antimony, arsenic, barium, beryllium, cadmium, cesium, lead, mercury, platinum, thallium, tin, and uranium), and their associations with salivary microbiome composition and dental decay in 61 children and adults. We hypothesized that there will be changes in the salivary microbiome composition in response to salivary metal levels which may directly affect oral health. Lack of information on how metals affect the oral bacterial community, and second, the lack of a comprehensive study of multiple metals in saliva and their impact on the oral microbiome, and third, limited studies of the associations of metal levels and the presence of dental decay

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