Gut Microbiota Composition in Hypertensive Individuals from the Chaoshan Region: A 16S rRNA Cross-sectional Case-Control Study

Abstract

Background: Hypertension is a major global health burden that involves complex gene–environment interactions. Emerging evidence links gut microbiota dysbiosis to hypertension; however, population-specific patterns in genetically distinct cohorts remain underexplored. Objectives: To characterize the gut microbiota composition in hypertensive individuals from China’s Chaoshan region and to describe how composition varies across demographic and metabolic strata. Methods: We conducted an unmatched cross-sectional case-control study of 50 antihypertensive-naïve participants (34 hypertensive and 16 normotensive) recruited from the Chaoshan region. Fecal 16S rRNA V4 sequences generated using the Illumina HiSeq 2500 platform were clustered into operational taxonomic units at 97% similarity and annotated against SILVA (v132). Analyses included alpha- and beta-diversity assessments (analysis of similarities and multi-response permutation procedure), exploratory linear discriminant analysis effect size (LEfSe) ranking (linear discriminant analysis, LDA > 2.0), and descriptive stratified comparisons. Results: Hypertensive participants exhibited lower alpha diversity (Chao1, ACE, unadjusted P < 0.05) and modest community-structure separation (ANOSIM r = 0.149, P = 0.019), with a higher relative abundance of Firmicutes (73.7% vs 61.2%) and lower relative abundances of Bacteroidetes (12.1% vs 16.9%) and Proteobacteria (8.2% vs 17.3%). The group-mean Firmicutes-to-Bacteroidetes (F/B) ratio was 6.1 versus 3.6 (a descriptive index not computed per participant). Exploratory LEfSe ranking identified Blautia and Lachnospiraceae as the highest-ranking taxa in the hypertensive group. Within the hypertensive group, descriptive comparisons without formal statistical testing indicated variation in F/B ratios and family-level abundances across sex, age, Body Mass Index (BMI), and lipid categories. Conclusions: In this Chaoshan sample, hypertension was associated with a distinct, descriptively different gut microbiota composition. Given the cross-sectional design and the lack of host genotyping and dietary adjustment, these hypothesis-generating findings warrant confirmation in larger, genetically informed studies.