Fig. 1

In vivo confirmation of metabolic retroconversion of TMAO. Reduction of d₉-TMAO to d₉-TMA was quantified by UPLC–MS/MS up to 6 h after d₉-TMAO gavage and antibiotic treatment, together with unlabelled TMA and TMAO levels. Plasma quantification of post-gavage a d₉-TMA and b d₉-TMAO. *Significantly (P < 0.05; t test and corrected for multiple comparison using the Holm–Sidak method) different from the respective groups not treated with antibiotics. c d₉-TMA bioavailability (AUC). d d₉-TMAO bioavailability (AUC). Plasma quantification of post-gavage unlabelled/endogenous e TMA and f TMAO. *Significant between d₉ and d₉ antibiotic treatment; ^$significant between TMAO and TMAO antibiotic treatment. g Unlabelled/endogenous TMA bioavailability (AUC). h Unlabelled/endogenous TMAO bioavailability (AUC). Data (n = 6 per group) are shown as mean ± SEM (a, b, e, f). Differences between the bioavailabilities (c, d, g, h) were assessed using one-way analysis of variance (ANOVA), followed by Holm–Sidak post hoc tests. Data with different superscript letters are significantly different (P < 0.05)