Usefullness of a prebiotic mixture to increase calcium absorption and retention during normal growth and during recovery from protein malnutrition: experimental model in rats.

Abstract

Nutrition influences linear growth and bone mass accumulation, modulating the genetic potential. Colonic fermentation of galactooligosaccharides (GOS) and fructooligosaccharides (FOS) enhances Ca absorption.
Objective: To evaluate the effect of a mixture 9:1 of short-chain galacto-oligosaccharides (GOS) and long-chain fructo-oligosaccharides (FOS) (GOS/FOS®) during normal growth or recovering from early protein deprivation on Ca and P absorption and bone retention, in rats. Methods: The study was done in two groups of rats with different nutritional status. Normal growth: At weaning until day 40, male rats received one diet: AIN93-G containing: 0.5% Ca (Ca.5-40); 0.3% Ca (Ca.3-40); 0.3% Ca plus 5.3% GOS/FOS® (Ca.3P). Nutritional recovery: At weaning, rats received a low protein diet (4%) during a week. Then, these undernourished (U) rats were reefed with 0.5%Ca diet with or without 5.3% GOS/FOS® until 50 days of life (DCa.5-50 or DCa.5P50, respectively). A control nourished group was fed AIN93-G until 50 days of life. Food consumption, Ca, Mg and P absorption (mg/d and %), and lactobacilli development in fresh feces were evaluated weekly; caecum pH, femur mineral content, biomechanical and densitometric analysis (Lunar DXA) and biochemical bone markers were measured after sacrifice. Results: The prebiotic consumption increased lactobacilli development (p <0.0001); reduced caecum pH (p <0.0001); increased Ca, Mg and P absorptions (p <0.01). Moreover, prebiotic enhanced femur mineral content (p <0.05); densitometric (p<0.01), biomechanical (p <0.05) and biochemical parameters (p<0.01) in both experimental models as compared to the groups fed the prebiotic-free-diets. Conclusion: The prebiotic mixture studied here increased mineral absorption supplying an extra amount of bone minerals that beneficed bone acquisition.