Figure 3. The in vivo pharmacokinetic and pharmacodynamic properties of FMC and IMC.

a) (Left) Plasma TMAO levels 24 hours post-gavage of vehicle, 100 mg/kg FMC, or 100 mg/kg IMC in mice maintained on a choline-supplemented (1% w/w) diet. Significance determined by two-tailed Student’s t-test. (Center) Plasma TMAO levels (determined at 24 hours post-gavage) on the indicated days over a course of daily FMC or IMC treatment for 14 days. (Right) Relative activity (compared to vehicle controls) in mice treated by oral gavage with either vehicle (“No Addition”, NA) or the indicated range of doses (0.0001 – 310 mg/kg) of either FMC or IMC. For each inhibitor, two groups of mice were tested. In the “d₉-choline challenge” group (⋄), mice were maintained on a chemically-defined chow diet (0.08% w/w total choline) and simultaneously gavaged with 10 mg/mL d₉-choline plus the indicated dose of FMC or IMC as described in Methods; the relative activity was measured in blood collected 3 hours post-gavage as the amount of d₉-TMAO produced relative to the vehicle control (100%). In the “q24h post-gavage” groups (O), mice were maintained on a choline-supplemented diet (1% w/w) and treated with once-daily oral gavages of the indicated inhibitor and dose for 4 days; the relative activity represents plasma TMAO levels relative to the vehicle control in blood collected 24 hours after the last gavage (on day 5). Data points represent the mean ± SEM. Exact numbers of mice used for each data point can be found in the Source Data (n=4–14).

b) Plasma levels of (left) FMC and FMB and (right) choline, betaine, TMA, and TMAO at the indicated time points after a single oral gavage of FMC (100 mg/kg) in mice maintained on a choline-supplemented diet (1% w/w) for 3 weeks. Center, levels of FMC and FMB in fresh fecal samples, normalized to the dry weight of the samples. Data points represent the mean ± SEM for the indicated number of mice.

c) Concentrations of FMC, IMC, choline and TMA within the indicated intestinal luminal compartment 4 hours after a single gavage of either vehicle, 100 mg/kg FMC, or 100 mg/kg IMC in mice maintained on a choline-supplemented diet (1% w/w) for 3 weeks. Bars represent the mean ± SEM for the indicated number of mice.