Marshmallows, gummy bears, and Jell-O are all made jiggly by gelatin, an ingredient that comes from processed leftover pig and cow parts. If this troubles you, you may be glad to hear that some researchers are working on an alternative to animal-derived gelatin. Namely, gelatin that's human-derived.
Gelatin is made by breaking down collagen, a protein that's plentiful in mammals' connective tissues. Collagen's ropy molecules run through bones, skin, and tendons. Spare bones and hides from the meat industry (but not hooves, despite what you may have heard) are collected and processed to make gelatin. Collagen holds people together; gelatin holds Peeps together.
Gelatin also shows up in cosmetics (as "hydrolyzed animal protein"), pharmaceuticals (in vaccines and gel capsules), and paintballs (like an oversized Nyquil full of hurt). But gelatin's not a perfect product. The manufacturing process creates molecules of varying sizes, not the consistent product that the pharmaceutical industry would prefer. The animal proteins can trigger immune reactions in humans. And like any process that involves repurposing animal scraps, gelatin manufacturing carries a slight risk of spreading infections such as mad cow disease.
A group of researchers in China, in search of a better gelatin, have turned to humans. Rather than boiling up some human bones, they engineered yeast that can make human gelatin from scratch. The researchers inserted a set of human genes into yeast cells, and the cells used their own machinery to manufacture human collagen and process it into gelatin. Though the result had never been inside a human, it was human gelatin.
If this technique catches on, it could be a safer and more efficient way to make the gelatin we use in drugs and vaccines. It's hard to say whether human gelatin could ever catch on in the food industry, though. Gummy bears made with pig protein (or Twinkies made with beef fat) are one thing, but gelatin made from human genes--THAT would be gross.
Duan, H., Umar, S., Xiong, R., & Chen, J. (2011). New Strategy for Expression of Recombinant Hydroxylated Human-Derived Gelatin in Pichia pastoris KM71Journal of Agricultural and Food Chemistry, 59 (13), 7127-7134 DOI: 10.1021/jf200778r