Article Figures & Data
Figures
- Figure 1.
The average sum of O6MeG staining intensity for each dietary treatment (A). Resistant starch (RS) supplemented in the diet (B) significantly reduced DNA adduct formation (P < 0.01) as compared with those diets without resistant starch. Compared with casein, red meat (C) significantly increased adduct formation (P < 0.018) irrespective of protein amount. There was no effect of protein amount (D) on DNA O6MeG staining intensity irrespective of the protein source. Data are presented as means ± SE.
- Figure 2.
Average distribution of O6MeG formation (A) for each dietary treatment along the length of the crypt. The highest cell number represents the top of the crypt. Data represented as RoB ratio, a higher value represents a higher intensity of positive staining in the cell nucleus. Light microscopic image of distal colonic crypt (B) at 20× optical zoom showing distribution of O6MeG staining intensity. RS, resistant starch.
Tables
- Table 1.
Composition of experimental diets (g/100 g in diet)
Low casein High casein Low casein + RS Low meat High meat High meat + RS Caseina 17.6 35.3 35.3 — — — Red meata — — — 20.43 40.9 40.9 Corn starch 10 10 — 10 10 — High amylose maize starch — — 10 — — 10 Sucrose 45.48 27.78 27.78 46.39 29.69 29.68 Sunflower seed oil 12.5 12.5 12.5 12.5 12.5 12.5 Lardb 7.5 7.5 7.5 3.76 — — α-Cellulose 2 2 2 2 2 2 l-Cysteine 0.3 0.3 0.3 0.3 0.3 0.3 Choline 0.12 0.12 0.12 0.12 0.12 0.12 Mineralsc 3.5 3.5 3.5 3.5 3.5 3.5 Vitaminsc 1.0 1.0 1.0 1.0 1.0 1.0 -
↵aEnough casein and red meat were added to reach a total protein content of 15% for the low protein diets and 30% for the high protein diets.
-
↵bLard was added to the casein and low red meat diets to balance each diet for saturated fat and to give a total fat content of 20%.
-
↵cAIN-76 vitamin and mineral mixtures with modified calcium at 0.5 mg/g, phosphorus at 3.6 mg/g, folic acid at 0.23 μg/g, and vitamin D3 at 0.11 IU/g.
-
- Table 2.
Effect of dietary protein amount, protein type, and resistant starch supplementation on fecal fermentation measuresa
Treatment groups Pb Low casein High casein High casein + RS Low meat High meat High meat + RS Protein amount Protein type RS Fecal pH 7.8 ± 0.1 7.5 ± 0.1 6.9 ± 0.6 7.2 ± 0.1 7.6 ± 0.1 6.7 ± 0.1 0.91 0.09 <0.0001 Acetate, μmol/g 16.8 ± 2.8 20.0 ± 3.4 28.0 ± 3.6 28.1 ± 4.6 25.3 ± 4.7 41.4 ± 3.9 0.76 0.07 <0.0001 Propionate, μmol/g 4.7 ± 0.6 4.9 ± 0.6 17.9 ± 2.2 6.4 ± 0.7 6.9 ± 0.9 26.4 ± 2.1 0.21 0.01 <0.0001 Butyrate, μmol/g 2.9 ± 0.6 3.5 ± 0.4 12.2 ± 1.7 3.9 ± 0.6 6.2 ± 1.7 17.4 ± 2.1 0.15 0.08 <0.0001 Total SCFAs, μmol/g 24.0 ± 3.8 28.4 ± 4.3 58.1 ± 7.0 38.4 ± 5.6 38.4 ± 6.2 85.2 ± 7.2 0.91 0.039 <0.0001 Ammonia, μmol/mL 6.5 ± 1.5 8.3 ± 1.9 4.5 ± 0.9 4.1 ± 0.3 6.3 ± 1.6 3.7 ± 0.4 0.19 0.15 0.05 Phenol, μg/g 1.5 ± 0.3 1.4 ± 0.3 0.2 ± 0.1 1.3 ± 0.3 1.9 ± 0.3 0.9 ± 0.3 0.29 0.53 <0.0001 p-Cresol, μg/g 3.8 ± 0.4 3.9 ± 0.8 2.2 ± 0.1 5.9 ± 0.9 7.4 ± 0.8 6.2 ± 0.6 0.48 <0.0001 0.16 - Table 3.
Effect of dietary protein amount, protein type, and resistant starch supplementation on distal colon epithelial cell kineticsa
Treatment groups Pb Low casein High casein High casein + RS Low meat High meat High meat + RS Protein amount Protein type RS Crypt height (cells) 22.3 ± 0.5 21.9 ± 0.6 23.1 ± 0.4 22.5 ± 0.6 22.3 ± 0.4 23.2 ± 0.4 0.62 0.59 0.03 Proliferation (cells per crypt) 3.7 ± 0.2 3.3 ± 0.2 3.7 ± 0.3 3.5 ± 0.2 3.5 ± 0.1 4.2 ± 0.4 0.39 0.85 0.04 Apoptosis (cells per crypt) 0.3 ± 0.1 0.2 ± 0.1 0.2 ± 0.03 0.3 ± 0.1 0.3 ± 0.1 0.1 ± 0.02 0.37 0.73 0.001 - Table 4.
Relationships between fermentation products, epithelial kinetics, and adduct formationa
Fecal pH Ammonia p-Cresols Phenols Acetate Propionate Butyrate Total SCFAs Crypt height Pearson correlation −0.206 −0.130 −0.079 −0.100 0.240 0.215 0.114 0.244b P 0.09 0.30 0.52 0.41 0.05 0.09 0.40 0.05 Proliferation Pearson correlation −0.024 −0.159 −0.026 −0.194 0.059 0.197 0.177 0.163 P 0.85 0.21 0.83 0.11 0.64 0.12 0.18 0.20 Apoptosis Pearson correlation 0.224 −0.175 −0.015 0.161 −0.199 −0.362c −0.325b −0.320b P 0.07 0.16 0.90 0.19 0.11 0.003 0.013 0.01 Sum of O6MeG Pearson correlation 0.377c −0.064 0.234b 0.046 0.029 −0.214 −0.234 −0.096 P 0.002 0.61 0.049 0.70 0.81 0.09 0.07 0.45
Volume 4, Issue 11
