Enhanced intestinal absorption of micronutrients in streptozotocin-induced diabetic rats maintained on zinc supplementation

In view of the deficiency of zinc concomitant with other minerals in diabetic condition, it is desirable to increase the absorption capability of the same by improving the intestinal health. In continuation of our previous report on the virtue of zinc supplementation on diabetic complications, and a significant favourable consequence in the restoration of the compromised structural integrity of small intestines in diabetic situation, it would be relevant to examine the permeability characteristics of the intestines. Groups of hyperglycemic rats were treated for six weeks with supplemental zinc (5-times and 10-times of normal level) to examine its possible influence on intestinal absorption of trace elements zinc, iron and calcium. Everted segments of isolated duodenum, jejunum and ileum portions of small intestine excised from these rats were evaluated for ex vivo uptake of iron, zinc and calcium from the incubation medium containing mineral fortified digesta of finger millet as a provider of these trace minerals. The extent of ex vivo uptake of zinc, iron, and calcium was severely compromised in the intestinal segments isolated from diabetic rats suggesting the loss of functional integrity concomitant with diminished ultra-structural integrity. This was more prominent in the case of iron uptake followed by that of calcium and zinc. Treatment with supplemental zinc improved the mineral uptake ex vivo by the isolated intestinal segments, which was maximum for iron followed by zinc and calcium. This favourable influence was seen more in the jejunal segment probably as a result of improving the expression of applicable transporter protein (s) as observed previously. Thus, dietary zinc supplementation was evinced here to have a promoting stimulus on the intestinal absorption of zinc, iron and calcium, which could encourage a dietary approach to counter the dyshomeostatic state of these trace elements prevalent in diabetes.