Over the 6-week experimental period, food intake and initial body weight were the same in all groups (Table 1). However by the end of the 6th week, the final body weight increased in all five groups of mice. The incremental increase in weight, however, was larger in the STD group (21.35 ± 0.87 to 25.01 ± 0.14 g). Alternatively, weight gain in the STD and SHAM groups was higher (3.66 ± 0.37 and 3.38 ± 0.30 g, respectively) (Table 1). The results in Table 1 show that glucose levels decreased in all mice independently of the diet but there was a significant decrease in mice fed with fructans over the course of the experiment.
In general, groups fed diets supplemented with fructans showed a tendency increase fecal excretion compared to the STD group (CAF1 = 9.31 ± 0.12 g, CFA2 = 10.35 ± 0.15 g, RNE = 8.84 ± 0.11 g, STD = 7.34 ± 0.23 g, and SHAM = 8.34 ± 0.12 g) (Table 1). However the increment was not significant.
Short Chain Fatty Acids
With respect to SCFA concentration in the caecum, the groups fed diets supplemented with fructans (CAF 1, CAF 2, and RNE) showed increased SCFA content compared to the standard diet groups (STD, SHAM). However, the CAF1 group had the highest concentration of SCFAs (Table 2) and acetate and butyrate in the caecum (34.72 ± 1.01 mmol/Kg and 18.67 ± 2.13 mmol/Kg, respectively). CAF2 had the highest concentration of propionate (25.64±1.03 mmol/Kg). The concentration of SCFAs in the colon showed the same trend observed for the caecum where CAF1 had a greater rise in total concentration of SCFAs (Table 2) and in the individual concentrations of acetate and butyrate (44.03 ± 1.91 mmol/Kg and 16.21 ± 2.00 mmol/Kg, respectively).
Calcium and Magnesium Analysis
Calcium content in plasma (mg/L) was similar in all mice groups at the beginning of the experiment (Fig. 1). Nevertheless, the STD group showed decreased calcium content in the third and sixth week (63.5 and 53.1, respectively) from a starting content of 67.8 mg/L. The groups fed fructan-supplemented diets and the SHAM group presented a slight, but not statistically significant, decrease in calcium content. No difference was observed in magnesium content for the entire duration of treatment (Fig. 1).
The most relevant results of this study pertain to the effect of the prebiotics used on mineral absorption and retention in bone (Table 3). The CAF1 mice showed the highest increase in apparent absorption (38%) and retention (20%) of the mineral in bone. However, the other groups also showed an incremental increase in absorption and retention (CAF2: 36% and 18%; RNE: 34% and 18%, respectively). On other hand, calcium and magnesium content in the plasma increases incrementally in both mice groups fed diets supplemented with Agave fructans. Moreover, the levels of calcium in the plasma show slight changes over the course of the experiment and in the sixth and final week, the groups fed diets supplemented with fructans were able to overcome the...