Lifestyle plays an important role in shaping the gut microbiome. However, its contributions to the oral microbiome are less well understood. This study characterized oral microbiomes across Nepali populations representing a gradient of lifestyles from traditional, rural settings to industrialized, urban environments. The findings reveal that oral microbial communities shift along with dietary, hygienic, and environmental changes associated with industrialization, providing insights into how modernization affects human microbial ecology and health.