Figure 2.

Modeling of colonic PGE₂ concentrations as a function of serum EPA:AA ratios. These models allowed subsequent use of the serum EPA:AA ratio as a predictor of colonic PGE₂. Initially, the model contained only animal data, and it was updated as human data became available during the course of the trial in an adaptive, Bayesian design. Model 1: animal only data; Model 2: posterior based on adding 10 human participants; Model 3: posterior based on adding 18 participants to the animal data. The fourth model with 27 participants was not utilized for dosing in the present trial as it essentially converged with Model 3. The equations for the lines of natural log of colonic PGE₂ (ng/mg protein) as the dependent variable versus serum EPA:AA ratio are: animal data, y = 4.15 – 1.38 × x (Model 1); posterior with 10 participants added, y = 4.15 – 1.70 × x (Model 2); posterior with 18 participants added, y = 4.12 – 1.96 × x (Model 3); posterior with 27 participants added, y = 4.0 – 2.03 × x (Model 4). The models were used to determine the serum EPA:AA ratio needed to achieve the desired colonic PGE₂ concentration in each individual.