Effects of environmental metal exposure on human oral microorganisms

Environmental heavy metals, as persistent contaminants, can enter the human oral cavity through the food chain, posing significant public health risks. This study investigates the long-term effects of environmental heavy metal exposure on oral bacterial communities and resistance genes in residents. As a result of long-term residence in areas with relatively high heavy metal contamination, exposure to heavy metals has led to alterations in the oral bacterial structure and influenced the interactions among bacterial species and resistance genes. Certain oral bacteria act as potential hosts for resistance genes, with co-selection playing a pivotal role in the persistence of bacterial resistance under environmental metal exposure. Therefore, in future prevention and control efforts, we suggest that in addition to strengthening water management and soil remediation to reduce heavy metal concentrations in the environment, a human oral microbiota monitoring system should be established to regularly assess the oral microbiota status of the local population so that timely interventions can be taken.