A comparative study of the gut microbiome and fecal metabolome in hypertensive patients from middle-temperate and tropical cities of China: Daqing and Haikou

Background Geographic variations in climate and lifestyle may be associated with hypertension (HTN) through alterations in the gut microbiota and its metabolites. This study aimed to comparatively analyze the gut microbiome and fecal metabolome of hypertensive patients from two Chinese cities characterized by distinct climatic conditions: Daqing (middle-temperate climate) and Haikou (tropical climate). The objective was to identify gut microbial and metabolic characteristics associated with geographic differences and to provide insights into HTN prevention and management. Methods A cross-sectional study was conducted between May and December 2024, involving hypertensive patients from Daqing and Haikou. Fecal samples were collected from 28 hypertensive patients in Daqing (DQ group) and 32 in Haikou (HK group), and analyzed using shotgun metagenomic sequencing and untargeted metabolomics. Results Differences in microbial composition and metabolite profiles were observed between the two groups. Using ALDEx2 analysis at the genus level, 34 genera were identified as differentially abundant between the DQ and HK groups. After adjusting for potential confounding variables, including age, body mass index, smoking, and drinking status, 6 genera remained significantly associated with geographic grouping. A logistic regression model based on these genera achieved an area under the curve (AUC) of 0.8069, with Pseudescherichia showing the highest individual discriminatory performance (AUC = 0.7925). Functional analysis suggested that pathways such as xylene degradation and biofilm formation were relatively reduced in the DQ group. Metabolomic analysis identified 38 differentially abundant metabolites, including 15-hydroxyeicosatetraenoic acid (15-HETE), 7α,25-dihydroxycholesterol, the putative metabolite (3-hydroxypentadecanoyl) lysine, and ginsenoside Rg3. Dysregulated pathways were mainly involved in glycerophospholipid metabolism, ABC transporters, and choline metabolism. Correlation analysis revealed potential associations between differential microbes and metabolites. Conclusion Distinct gut microbiome and metabolome profiles were observed between hypertensive patients from the two geographic regions. These findings suggest potential associations between environmental factors and host-microbiome-metabolite interactions.