Association Analysis Between Gut Microbiota Characteristics and Body Weight of Maritime Workers

Background Overweight is highly prevalent among maritime workers due to occupational characteristics such as restricted dietary supply, disrupted circadian rhythms and limited physical activity. Gut microbiota acts as a key mediator linking dietary factors to host energy metabolism and weight regulation. This study aimed to investigate the association between gut microbial characteristics and body weight in maritime workers, so as to provide scientific evidence for nutritional intervention and weight management in this population. Methods Twenty-four long-term maritime workers were divided into a normal weight group (n = 12) and an overweight group (n = 12) according to body mass index. Fecal samples were collected from all participants, and metagenomic sequencing and untargeted fecal metabolomics were performed to compare gut microbial composition and metabolic profiles between the two groups. Results The overweight group showed significantly lower gut microbiota alpha diversity and distinct beta diversity compared with the normal weight group (all P < 0.05). The overweight group had higher relative abundances of Escherichia coli and Blautia spp. , and lower relative abundances of Clostridiales, Bacteroides faecis and Ruminococcus faecis . Metabolomic analysis revealed significant alterations in lipids and lipid-like molecules in the overweight group, with notable reductions in melatonin and its precursor molecules (all P < 0.05). Conclusion Overweight maritime workers present gut microbiota dysbiosis and impaired nutrition-related metabolic pathways, which are closely associated with unreasonable dietary patterns and decreased sleep quality in this occupational population. These findings provide a theoretical basis for improving weight status through dietary regulation and gut microbiota modulation in maritime workers.