Gut Microbiota Dysbiosis Is Associated with Cardiometabolic Risks in Young Males Living in a Marine Environment: A Cross-Sectional Study

Background Long-term marine environment exposure is characterized by restricted dietary supply, altered lifestyle patterns, and unique environmental stressors, which may disrupt gut microbiota homeostasis and elevate cardiometabolic risks in exposed populations. However, the association between gut microbiota and cardiometabolic phenotypes in marine-resident populations remains poorly characterized from a public health perspective. Methods This cross-sectional study enrolled 157 young male subjects (aged 18–26 years) who had lived and worked in a marine environment for at least one year. Gut microbiota profiles were analyzed via 16S rRNA gene sequencing targeting the V3/V4 regions. Dietary, lifestyle, and biochemical data were collected through validated questionnaires and clinical biochemical assays. Association analyses were performed to identify links between gut microbiota features and host cardiometabolic phenotypes. Results Reduced gut microbial alpha diversity was observed in participants with hyperlipidemia and hyperuricemia. Dietary factors including rice intake, balanced diet patterns, and egg consumption were positively associated with microbial diversity, while vitamin supplement intake showed a negative association. Specific taxa (e.g., Christensenellaceae_R-7_group and Paracoccus) and inferred metabolic pathways (e.g., phosphatidylinositol signaling pathway) were significantly associated with cardiometabolic-related phenotypes. The prevalence of metabolic syndrome and hyperuricemia in the cohort was 20.3% and 13.4%, respectively. Conclusions Gut microbiota dysbiosis is associated with cardiometabolic phenotypes in young adult males living in a marine environment, with diet and lifestyle factors serving as important mediators. These findings provide public health evidence for developing targeted environmental health interventions for populations in marine settings.