In general, fiber and fiber compounds found in cereals can reduce mineral absorption in humans. These minerals include manganese, zinc, magnesium and calcium.
One way to solve this problem is to add soluble forms of fiber. These include inulin, oligofructose, lactulose, resistant starches, gums and pectins. Studies have shown that these soluble fibers can make gut contents more viscous and allow the cecum to ferment and produce volatile fatty acids.
Soluble forms of fiber have also been shown to increase concentrations of serum enteroglucagon, and have a trophic effect on animals’ ceca, which makes better fermentation of any remaning coarse materials.
In other words, there is clearly better absorption of minerals by adding soluble forms of fiber. In the future, scientists should also study the effects of indigestible carbohydrates in the mineral absorption among humans.
Indigestible carbohydrates are important for a variety of reasons. First, indigestible sugars like FOS or fructooligosaccharides have stimulatory effects on mineral absorption.
Currently, research has shown that FOS is indigestible by human enzymes. Studies involving rats show that FOS helps increase both true and apparent intestinal calcium. FOS is also found to increase magnesium absorption from cocoa, rice bran, and other natural foods.
However, magnesium and calcium absorption is reduced by cecectomy. In fact, both nutrients disappear as the colorectal contents move from the cecum towards the anus. One way to increase calcium and magnesium absorption in the cecum is through increased dietary FOS.
It now seems that FOS is stimulated in the large intestine, especially since its been show that calbindin-D9k is increased with intake of dietary FOS.
Dietary FOS also prevents osteopenia in both gastrectomized and ovariectomized rats. Among gastrectomized rats, dietary FOS also keeps them from getting anemia.
Magnesium absorption is decreased when a diet is rich in phosphorus and calcium content. In fact, when rats are given this kind of diet, they soon exhibit symptoms typical of magnesium deficiency. However, a FOS diet curbs these symptoms.