Eighty percent of the world's illness is caused by fecal matter. A gram of feces can contain 10 million viruses, 1 million bacteria, 1,000 parasite cysts, and 100 worm eggs. Bacteria can be beneficial: the human body needs bacteria to function, and only 10 percent of cells in our body are actually human. Plenty are not. Small fecal particles can then contaminate water, food, cutlery, and shoes-and be ingested, drunk, or unwittingly eaten. One sanitation specialist has estimated that people who live in areas with inadequate sanitation ingest 10 grams of fecal matter every day.As with the space race, China is on the forefront of advances in human excrement, George says. It's not just innovation in toilet technology like the ping pong john below: the energy that comes from the fermenting of feces is called biogas, and pig feces and human feces are the primary source to fuel stoves for cooking.