Dietary fibre and protein do not synergistically influence insulin, metabolic or inflammatory biomarkers in young obese Gottingen minipigs

The effects of dietary fibre (DF) and protein on insulin response, lipidaemia and inflammatory biomarkers were studied in a model experiment with juvenile obese Gottingen minipigs. After 20 weeks feeding on a high-fat fructose-rich low-DF diet, forty-three 30-week-old minipigs (31 center dot 3 (sem 4 center dot 0) kg body weight) were allocated to low- or high-DF and -protein diets for 8 weeks in a 2 x 2 factorial design. High DF contents decreased (P = 0 center dot 006) while high protein increased (P < 0 center dot 001) the daily gain. High protein contents increased fasting plasma concentrations of glucose (P = 0 center dot 008), NEFA (P = 0 center dot 015), ghrelin (P = 0 center dot 008) and non-fasting LDL:HDL ratios (P = 0 center dot 015). High DF increased ghrelin (P = 0 center dot 036) and C-peptide levels (P = 0 center dot 011) in the non-fasting state. High protein increased the gene expression of fructose-bisphosphatase 1 in liver tissue (P = 0 center dot 043), whereas DF decreased fatty acid synthase expression in adipose tissue (P = 0 center dot 035). Interactions between DF and protein level were observed in the expression of leptin receptor in adipose tissue (P = 0 center dot 031) and of PPAR gamma in muscle (P = 0 center dot 018) and adipose tissue (P = 0 center dot 004). In conclusion, high DF intake reduced weight gain and had potential benefit on beta-cell secretory function, but without effect on the lipid profile in this young obese model. High dietary protein by supplementing with whey protein did not improve insulin sensitivity or lipidaemia, and combining high DF with high protein did not alleviate the risk of metabolic abnormalities.