The Association Between Circulating 25-Hydroxyvitamin D and Carotid Intima-Media Thickness is Mediated by Gut Microbiota and Fecal and Serum Metabolites in Adults.

ScopeVitamin D is vital to cardiovascular health. This study examines the association between plasma 25-hydroxyvitamin D (25[OH]D) and the progression of carotid intima-media thickness (cIMT) and identifies the potential mediating biomarkers of gut microbiota and metabolites in adults. Methods and ResultsThis 9-year prospective study includes 2975 subjects with plasma 25(OH)D at baseline and determined cIMT every 3 years. Higher circulating 25(OH)D is associated with decreased odds of higher (& GE;median) 9-year cIMT changes at the common carotid artery (h & UDelta;CCA-cIMT) (p-trend < 0.001). Multivariable-adjusted OR (95%CI) of h & UDelta;CCA-cIMT for tertiles 2 and 3 (vs. 1) of 25(OH)D is 0.87 (0.73-1.04) and 0.68 (0.57-0.82). Gut microbiome and metabolome analysis identify 18 biomarkers significantly associated with both 25(OH)D and h & UDelta;CCA-cIMT, including three microbial genera, seven fecal metabolites, eight serum metabolites, and pathway of synthesis and degradation of ketone bodies. Mediation/path analyses show the scores generated from the overlapped differential gut microbiota, fecal and serum metabolites, and serum acetoacetic acid alone could mediate the beneficial association between 25(OH)D and h & UDelta;CCA-cIMT by 10.8%, 23.1%, 59.2%, and 62.0% (all p < 0.05), respectively. ConclusionsThese findings show a beneficial association between plasma 25(OH)D and the CCA-cIMT progression. The identified multi-omics biomarkers provide novel mechanistic insights for the epidemiological association.