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Watching Your Food Digest--In a Fake Gut

The human digestive tract. Can you find your food?

Have you ever wondered what happens to your food after you swallow? Well, we all know that it goes down to the stomach and it starts making some really weird noises. That's because it's digesting.

But, do you know what's actually happening? Now, there is a way to see what's going on down there.

ARS human physiologist (fizz-ee-ah-lo-jist) Raymond Glahn with the U.S. Plant, Soil and Nutrition Laboratory in Ithaca, New York, has invented a fake gut.

The gut will help him understand how our bodies use the nutrients in the food we eat. Dr. Glahn's fake gut uses cells from the human intestine called Caco-2.

The gut is the first to model in the lab what happens in a human intestinal tract. Most important, it shows the food digestion process and absorbs nutrients just like the real thing.

Fake gut guy Raymond t Glahn, at the U.S. Plant, Soil and Nutrition Lab, in Ithaca, New York

Imagine being able to watch your pizza, soda, ice cream and popcorn all mix together in one big bowl of mush. You'd probably rather be watching TV, but watching food is Dr. Glahn's job.

He puts foods such as cereals, baby formulas, rice and corn into the fake gut. He chose these foods because of how much iron they have.

Whoa, where'd it go!


Iron is an important nutrient for people to eat, so scientists want to learn more about it. Still, many people, particularly women and young children, often don't get enough iron in their diet.

Without enough iron, you don't form enough red blood cells and thus don't get enough oxygen. You could then have a condition called anemia (ah-nee-mee-ah) that makes you weak, tired, pale and cranky.

It is especially important for mothers to get enough iron when they are going to have a baby so that the baby is healthy.

"Yikes, not another one!"

Dr. Glahn is trying to measure how much of the iron in foods our body actually absorbs. He is using the fake gut because it is too hard and expensive to do this experiment with animals. It costs a lot of money and the animals get full, unlike the fake gut.

monster burger aaaahh!

The clock is ticking It takes the fake gut three hours to digest all of the food. After it digests, Dr. Glahn measures the amount of ferritin (fair-ah-tin), an iron storage protein, to see how much of the iron was absorbed.

Orange juice is one source of vitamin C.

So far, Dr. Glahn and his team have found that adding vitamin C to rice cereal increases the amount of iron that the body absorbs. It's not only how much iron a food has that's important, but how your body uses it.

There are more than 2 billion people in the world suffering from iron malnutrition. This research can help food companies improve nutritional content of their products. It will also help scientists to find out how much iron and zinc are found in important foods like beans, corn, wheat and cassava.

Sweet tasting orange juice has vitamin C.

--By Sarah Tarshis, based on an Agricultural Research magazine article by Hank Becker, Information Staff, Agricultural Research Service.

If you really want to get into Dr. Glahn's fake gut work, then click here and read the magazine's longer version.

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