Extended Data Figure 4: Increasing total caloric intake leads to increased acetate turnover and GSIS via the microbiota in rats.

a, b, Plasma acetate and whole-body acetate turnover. c, d, Plasma glucose and glucose infusion rate during a hyperglycaemic clamp. e, f, Plasma insulin and insulin AUC during the clamp. g, Caloric intake from protein, fat, and carbohydrate. In g–m, each group was compared to pair-fed, high-carbohydrate-fed rats. h, i, Plasma glucose and glucose infusion rate in the hyperglycaemic clamp. j, k, Plasma acetate and whole-body acetate turnover. l, m, Plasma insulin and insulin AUC during the hyperglycaemic clamp. n, Linear regression: whole-body acetate turnover versus total caloric intake in each diet group. o, p, Plasma glucose and glucose infusion rate during a hyperglycaemic clamp in 4-week HFD-fed rats treated with broad-spectrum non-absorbable antibiotics. q, Plasma acetate. r, Plasma [¹³C]acetate enrichment following three days of feeding [¹³C]bicarbonate food and water. Data were compared using the two-tailed unpaired Student’s t-test. s, Insulin AUC during a hyperglycaemic clamp. In all panels, data are the mean ± s.e.m. of n = 6 rats per group, with groups compared by one-way ANOVA with Bonferroni’s multiple comparisons test, unless otherwise stated. In a–f, *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 versus 12-h starved rats; §P < 0.05, §§P < 0.01, §§§P < 0.001, §§§§P < 0.0001 versus 48-h starved rats. In h–m, *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001 versus pair-fed rats given the high-carbohydrate diet. In o–s, ***P < 0.001, ****P < 0.0001 versus HFD-fed rats; §§§P < 0.001, §§§§P < 0.0001 versus antibiotics-treated rats.