Effects of heavy metal exposure on oral microbial communities in women with different menopausal status

This study investigates the effects of long-term heavy metal exposure on the oral mucosal microbiota in women. By measuring both external environmental heavy metal exposure and internal heavy metal exposure indicators in the human body, it aims to elucidate the complex interactions between external environmental exposure and internal exposure, as well as their potential association with menopausal status. We analyzed oral microbial composition, function, and co-occurrence networks in 47 women from polluted and control areas. Heavy metal exposure significantly altered oral microbial diversity and functional pathways, with molybdenum (Mo) exhibiting a uniquely strong influence. Key metabolic pathways related to cardiovascular disease and carbohydrate metabolism were enriched in specific groups. Network analysis revealed a loss of keystone species and structural simplification in postmenopausal women from the polluted area. These findings suggest that heavy metal exposure alters oral microbial communities, and these alterations correlate with shifts in host metabolic pathways that are known to be associated with menopausal hormonal changes, potentially impacting women's health during this transition.IMPORTANCEThis study reveals, for the first time, how chronic heavy metal exposure and menopause interact to disrupt the female oral microbiome. We identify Mo as a key metal, correlating strongly with specific bacteria and linked to downregulated cardiovascular and metabolic pathways. Critically, postmenopausal women in polluted areas exhibit a severe loss of keystone species and a collapsed microbial network structure. These findings position the dysregulated oral microbiome as a potential mechanistic link between environmental metal exposure and the heightened systemic risks-such as metabolic disorders and chronic inflammation-observed in postmenopausal women, highlighting new targets for preventive health strategies.