Your intestines are quite important, and you’d be ill advised to part with a single foot of the stretchy tubing. However, it just so happens that the resilient tissue that lines your gut lends itself to a host of arts and crafts. Humans have capitalized on this with the help of other animals. In fact, we’re downright notorious in the animal kingdom for putting the intestines of other species to work in a variety of creative ways. Here are some examples:
• Cheese-making. Cow, sheep, and goat guts contain rennet, an important additive in the cheese-making process. Presumably, ancient man discovered this while making cheese in a convenient sack—the stomach of a dead animal.
• Music-playing. For centuries, craftsman fitted violins and other stringed instruments with tough fibers made from animal intestines. Although silk, nylon, and steel are more common today, some top-caliber musicians insist that nothing can match the sound of fresh sheep gut.
• Food. Natural sausage casings (the thin, plasticky substance that wraps your breakfast sausage) use animal gut from a pig, cow, or sheep.
• Sex. The world’s oldest known condoms (dating back to about 1640) were made from sheep intestines. They were quite expensive, which probably accounts for the roaring trade in washed, second-hand condoms that prevailed at the time.
Source of Information : Oreilly - Your Body Missing Manual