Figure 4. Effect of bifidobacteria treatment on short-chain fatty acid (SCFA) levels, glucagon-like peptide-1 (GLP-1) secretion, and the correlation between the two variables.

(a) SCFA levels in the caecum after 7 weeks of probiotic treatments. (b) Plasma acetate concentration. (c) Colonic GLP-1 levels measured using enzyme-linked immunosorbent assay. (d) Plasma GLP-1 levels and the area under the curve 0–30 min after oral glucose challenge in mice fed a high-fat diet with 6 weeks of probiotic treatments. (e) Correlation analysis between caecal acetate levels and visceral fat accumulation, plasma acetate levels and GLP-1 levels. (f) Correlation analysis between plasma acetate levels and visceral fat accumulation and adipocyte size. Pearson’s R correlation and corresponding P value are presented. Data represent the mean ± SEM. Tukey–Kramer multiple comparison test was used to assess the differences between the groups. Different letters next to bars indicate a significant difference (P < 0.05).