Results: From baseline, serumacetateconcentration were increased by the Prot (β: 0.24; 95% CI: 0.12, 0.35), Unsat (β: 0.21; 95% CI: 0.10, 0.33), and Carb (β: 0.12; 95% CI: 0.01, 0.24) diet; between diet, only Prot compared with Carb was significant (P = 0.02). Propionate was decreased by the Carb (β: -0.10; 95% CI: -0.16, -0.03) and Unsat (β: -0.10; 95% CI: -0.16, -0.04) diet, not the Prot diet; between diet comparisons of Carb vs. Prot (P = 0.006) and Unsat vs. Prot (P = 0.002) were significant. The Prot dietincreasedbutyrate (β: 0.05; 95% CI: 0.00, 0.09) compared with baseline, but not compared with the other diet. Increases in acetate were associated with decreases in insulin and glucose; increases in propionate with increases in leptin, LDLcholesterol, and blood pressure; and increases in butyrate with increases in insulin and glucose, and decreases in HDLcholesterol and ghrelin (Ps < 0.05).
Conclusions: Macronutrient composition of high-fiber diet affects circulating SCFAs, which are associated with measures of appetite and cardiometabolic health. This trial was registered at clinicaltrials.gov as NCT00051350.