After credibility assessment, no outcome presented convincing evidence; 6 (33%) health outcomes presented highly suggestive evidence (class II: CVD mortality, hypertension, MACE, all-cause mortality, DM, GFR); 3 (17%) presented suggestive evidence (class III: stroke, CVD, and CRC); and 5 (28%) presented weak evidence (class IV: SBP, BMI, TC, CRP, and GDM) for their associations with circulating TMAO concentrations. This evidence concerns the gene CRP and diabetes mellitus.