For more than 2 million people in the U.S. who suffer from celiac disease, traditional staples like wheat bread and pasta are off the menu.
With celiac, the body's immune system reacts to gluten -- the protein that gives breads, pasta and cereal their chewy, crunchy texture -- causing nausea, cramps, malnutrition and other health problems. There is no treatment for celiac other than avoiding foods made with wheat or eating an enzyme supplement with every meal.
Working together, scientists at Washington State University, Clemson University and partner institutions in Chile, China and France developed a new genotype of wheat with built-in enzymes designed to break down the proteins that cause the body's immune reaction. Their discovery, published in Functional and Integrative Genomics, opens the door to new treatments for celiac and for new wheat crops with a built-in defense against the disease.
The scientists introduced new DNA into wheat, developing a variety that contains one gluten-busting enzyme (or glutenase) from barley and another from bacteria Flavobacterium meningosepticum. These enzymes break down gluten proteins in the human digestive system.
Simulating the human body's digestive tract, scientists tested gluten extracts from the experimental grain and found that it had far fewer levels of the disease-provoking proteins. The enzymes reduced the amount of indigestible gluten by as much as two thirds.
These wheat genotypes open new horizons for treating celiac disease through enzymes in the grains and food, while increasing agricultural potential for the staple grain.
"Food made from wheat with glutenases in its grains means people with celiac don't have to rely on dietary supplements at every meal," said lead author Sachin Rustgi, assistant professor of molecular breeding at Clemson University and adjunct assistant professor with WSU's Department of Crop and Soil Sciences. "By packing the remedy to wheat allergies and gluten intolerance right into the grain, we're giving consumers a simpler, lower-cost therapy. We're also reducing the danger from cross-contamination with regular wheat, as the enzymes in our wheat will break down that gluten as well."
Calcium and pigs
In pig diets, the amount of digestible calcium has a direct impact on phosphorus digestibility and the overall growth performance of the animals. With more calcium, phosphorus digestibility and feed intake decrease, leading to lower-weight pigs.
For several years, Hans Stein, professor in the Department of Animal Sciences and the Division of Nutritional Sciences at the University of Illinois, has been working to establish the optimum ratio between the two minerals for pigs at various developmental ages. In an Animal Feed Science and Technology article, his research team determined that ratio for 50- to 85-kilogram pigs.
The team formulated 15 corn-soybean meal-based diets, varying in calcium and phosphorus concentration and fed them to 90 barrows over 30 days to determine growth performance.
"This study helped us confirm that we need to know the digestibility of calcium in pig diets and make sure we deliver exactly the right amount, rather than overfeeding," Stein said. "Our results indicate that to assure adequate bone mineralization without affecting growth performance, the ratio of STTD (standard total tract digestible) calcium to STTD phosphorus should be about 1.23:1 in diets for 50- to 85-kilogram pigs."