Effect of Probiotic, Prebiotic and Synbiotic Follow-up Infant Formulas on Iron Bioavailability in Rats

Abstract

The effect of functional ingredients-supplemented diets on iron bioavailability and the section of the large intestine involved with this effect was investigated in rats. The diets consisted of seven powder follow-up infant formulas containing probiotics ( Bifidobacterium bifidum and Bifidobacterium longum), prebiotics (galactooligosaccharides (4'-GOS) at 1.2, 5 and 10%) or synbiotics (bifidobacteria and 4'-GOS at 1.2, 5 and 10%) that were administered to weanling rats over 30 days. Iron balancing (mineral apparent absorption and retention ratios) was carried out in three periods of 72h each. Results showed that the administration of any of the test diets increased the apparent iron absorption or retention in any of the periods, however only 10% prebiotic and synbiotic diets significantly (P<0.05) increased apparent iron absorption and retention during the three periods of mineral balancing when compared to the control group. A linear regression study demonstrated that the stimulation of iron absorption took place mainly in the colon portion of the gut, since the parameters iron absorption, crypt depth of proximal colon and pH colon content showed a multiple linear relationship (R2=0.56). We concluded that 10% prebiotic and synbiotic diets were the diets most prone to improving iron bioavailability in the colons of rats.