Simulated Gut Measures Iron Available From Food

An artificial gut invented by Agricultural Research Service scientists promises to accelerate knowledge about the amount of iron available from food and food supplements. The system is the first to model in the lab what occurs in the human intestinal tract.

The research, led by ARS human physiologist Raymond P. Glahn, has already led to suggestions for improving the nutritional makeup of infant formula.

The model should have broad applications for studying staples like rice, corn, wheat and beans; food supplements; pharmaceutical iron preparations, and baby foods such as formula, cereals and purees, according to Glahn. He's based at the agency's U.S. Plant, Soil and Nutrition Laboratory in Ithaca, N.Y. ARS is the chief research agency of USDA.

Iron deficiency is the world's most prevalent nutrient deficiency. Even in developed countries, it remains a serious concern for women during pregnancy and childbearing years. Children, too, must receive proper iron nutrition.

To help solve the problem, Glahn and colleagues have developed an in vitro model. It couples simulated food digestion with a human intestinal cell line, Caco-2. The model allows food digestion to occur simultaneously with opportunity for nutrient uptake by Caco-2 cells.

So far, Glahn and co-workers have used the system to investigate iron availability of rice cereal, infant formulas and iron supplements. His model is a fast, inexpensive, easy method for determining the relative availability of iron from different foods or from different crop varieties of the same food.

The research team continues to improve and expand the model, which may eventually be used to measure bioavailability of other micronutrients, such as vitamin A, zinc, selenium and iodine. Future studies will determine iron and zinc bioavailability in other micronutrient-enriched, staple food crops including corn, wheat and cassava.

More details appear in a story in the August issue of Agricultural Research magazine and on the web at:

http://www.ars.usda.gov/is/AR/archive/aug99/iron0899.htm

Scientific contact: Raymond P. Glahn, ARS U.S. Plant, Soil and Nutrition Laboratory, Ithaca, N.Y., phone (607) 255-2457, fax (607) 255-1132, [email protected].