AUTHOR=Pei Shuwei , Feng Lu , Zhang Yonghua , Liu Jiangyun , Li Jia , Zheng Qiwen , Liu Xingrong , Luo Bin , Ruan Ye , Li Huan , Hu Weigang , Niu Jingping , Tian Tian 

TITLE=Effects of long-term metal exposure on the structure and co-occurrence patterns of the oral microbiota of residents around a mining area

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 14 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1264619

DOI=10.3389/fmicb.2023.1264619

ISSN=1664-302X

ABSTRACT=This study explores in depth the effects of long-term exposure to heavy metals on the microbiome of the buccal mucosa, helping us to better understand the relationship between environmental pollution and the oral  microbial ecosystem, as well as its potential health impacts. Subjects were divided into two groups: the exposure group and the control group. The most abundant bacteria identified at the phylum level were Firmicutes, Actinobacteriota, and Proteobacteria. Due to long-term exposure to heavy metals, the relative abundance of Rhodococcus, Delftia, Fusobacterium, and Peptostreptococcus increased, while the abundance of Streptococcus, Gemella, Prevotella, Granulicatella, and Porphyromonas decreased. The concentrations of heavy metals in the blood (Pb, Cd, Hg, and Mo) were associated with the growth of Rhodococcus, Delftia, Porphyromonas, and Gemella. In addition, the relative abundances of some pathogenic bacteria, such as Streptococcus anginosus, S. gordonii, and S. mutans, were found to be enriched in the exposure group. The microbial networks of the two groups were constructed based on the random matrix theory. Compared to the exposure group network, the control group network had a greater number of nodes, modules, interactive species, and keystone taxa and was therefore more complex and stable than the exposure group network. The shared nodes showed different topological roles. Module hubs and connectors in the control group converted into peripherals in the exposure group, indicating that keystone taxa changed. More importantly, the relative abundance of some keystone taxa (such as Solobacterium moorei and Prevotella salivae in this study) was very low, suggesting that relatively low-abundance bacteria may exert a greater influence on the entire microbial community than some bacteria with a relatively high abundance. In addition, we found that metals in the blood (Pb, Cd, Hg, and Mo) were drivers of the microbial network of the buccal mucosa, which can have adverse effects on the network, thus providing conditions for the occurrence of certain diseases. Altogether, this work should improve our understanding of environmental pollution and the structure of oral microbial communities.