Fig 2: Relative concentrations of A. GIP, B. GLP-1, C. insulin and D. glucose in the blood plasma of rabbits. Sodium butyrate was applied in the doses of 0.25 g/kg BW (referring to “Lower butyrate”) and 1.25 g/kg BW (indicated by “Higher butyrate”). Relative hormone concentrations were calculated by considering the baseline value of each animal at 0 min as 1. Results are expressed as mean ± SEM. Statistical analysis of data was performed by a randomized linear mixed model, asterisks indicate statistical significance compared to the 0 min values of the appropriate group (interaction between time and treatment), *P < 0.05.

Fig 3: Correlation between A. GIP and GLP-1, B. GIP and insulin, C. GLP-1 and insulin concentrations in the blood plasma of rabbits. Each data point refers to an individual animal according to its blood plasma hormone concentrations indicated on the axes. Squares refer to controls, circles to animals receiving the lower dose (0.25 g/kg BW) of butyrate and triangles to animals exposed to the higher dose (1.25 g/kg BW) of butyrate. Correlations were statistically analyzed by Pearson’s correlation test. The obtained correlation coefficients and P values were as follows: A. Coefficient: -0.22, P = 0.010; B. Coefficient: -0.15, P = 0.180; C. Coefficient: 0.22, P = 0.007.

Fig 4: Correlation between A. GIP and GLP-1, B. GIP and insulin, C. GLP-1 and insulin concentrations in the blood plasma of chickens. Each dot refers to an individual animal according to its blood plasma hormone concentrations, indicated on the axes. Correlations were statistically analyzed by Pearson’s correlation test. The obtained correlation coefficients and P values were as follows: A. Coefficient: 0.79, P < 0.001; B. Coefficient: 0.42, P < 0.001; C. Coefficient: 0.62, P < 0.001.