O-32 - Dietary choline or TMAO supplementation increases atherosclerosis in Apoe--- mice, correlating with plasma TMAO and not with plasma lipids
Own mouse experiment. The lipid-independence (no rise in cholesterol/TG/glucose) is central: it marks TMAO as a non-lipid atherogenic pathway.
Link to originalMethodology
Mixed design. HUMAN (rests on the Cleveland Clinic GeneBank/BioBank angiography cohort, D-4): untargeted plasma metabolomics in a prospective learning cohort (50 cases vs 50 matched controls, 3-year MI/stroke/death) and validation cohort (25 vs 25) identified choline, TMAO, and betaine; an independent 1,876-subject cohort tested dose-dependent association with prevalent CVD and angiographic burden. All human subjects were stable patients referred for elective coronary evaluation. MOUSE / mechanistic (own experiments, S-28): Apoe-/- mice fed control vs choline (0.5-1.0%) or TMAO (0.12%) chow for ~16 weeks; stable-isotope (d9-choline/d9-PC) tracer challenges in normal, antibiotic-treated, germ-free, and conventionalized mice; broad-spectrum-antibiotic suppression experiments; macrophage scavenger-receptor and foam-cell assays; and an F2 intercross mapping the FMO3 locus. COI: senior author Hazen holds patent/commercial interests in TMAO diagnostics (flagged across the Hazen-lab TMAO corpus).
Link to original
Why this is evidence
Direct TMAO supplementation raising aortic plaque, with plaque tracking plasma TMAO and not lipids, is predicted by H-15 and H-16 (a real causal mechanism). Under H-45 (TMAO a non-causal marker) manipulating TMAO itself should not increase atherosclerosis. Separates the marker pole from the two mechanism poles; does not by itself separate H-15 from H-16.