Generally, it’s not considered polite to talk about poop. And while that’s understandable, it’s also kind of a bummer. (Pun only-sort-of intended.) Because poop is fascinating. In the Nature of Things documentary Myth or Science: The Power of Poo, scientist Jennifer Gardy explores some popular poo myths and makes some remarkable discoveries. Poop is the end result of a complex biological process, and it turns out there’s a lot we can learn from it, both about ourselves, and the world around us.
Here are six ways poop is useful to us:
Poop can tell us about the health of our communities
Researchers at the Massachusetts Institute of Technology have invented a robot, called Luigi, that collects and analyzes sewer water. By looking at freshly flushed waste, they can find out a lot about a neighbourhood, including what people are eating, what medications they’re taking, or if they’re smoking. Most surprisingly, they can even measure a neighbourhood’s collective stress level based on what’s in the sewer.
There’s power in poop, literally
At Clovermead Farms in southwestern Ontario, a pioneering technology is turning manure into “cow power.” Twelve times a day, a machine scrapes cow poop from the barn floor and sends it to an anaerobic digester, a sort of giant, mechanical stomach. Microbes are added, and the manure is heated. That manure then produces methane gas, which powers a generator.
That generator creates enough energy to power five farms. As a bonus, the byproduct from turning poop to power is a nutrient-rich fertilizer, ideal for farming.
Poop can also power vehicles. The UK’s first “poo-bus” hit the road in Bristol in 2015. The bus runs on biomethane gas from sewage and inedible food waste.
Your poop can be an early warning system for gastrointestinal trouble
The ideal, healthy poop is the classic brown colour we all know and love. If your stool is black, though, that means you should see a doctor. Black stool can be an indicator of bleeding in the higher digestive tract. Similarly, red or maroon stool could mean lower digestive tract bleeding, caused by inflammatory bowel disease, diverticulitis, hemorrhoids, polyps or colorectal cancer.
The shape of your poop can also give you important information about whether or not you need more fibre, water, or a diet higher in probiotics.
What you shouldn’t worry about seeing is corn. Contrary to popular belief, corn in your stool doesn’t mean your digestive tract isn’t working. The shell of a corn kernel is made of insoluble cellulose, which can't be digested.
Poop can be weaponized
Skatole is what gives poop its unpleasant smell. When separated from the rest of the stool, it’s white and crystal-like. Skatole comes from tryptophan in mammals’ digestive tracts and is mildly toxic.
The US military has used skatole as a non-lethal weapon for years. It’s classified as a malodorant, which is a fancy way of saying it’s a military-grade stink bomb. Skatole has a toxicity level of three, on a scale of 1-4, in which one is the most toxic. That means it’s meant to induce gagging and vomiting.
The world’s best coffee comes from poop
Kopi luwak is a type of coffee made from beans that have been eaten, digested, and passed by an Asian palm civet — a small, cat-like omnivore that lives in the forests of Southeast Asia. Kopi luwak was first created in Indonesia but is also produced in the Philippines and East Timor.
The civets eat the coffee cherries, and their digestive tracts strip away the pulp of the cherry and ferment the bean, which is then pooped out. The beans are collected, washed (obviously), and roasted. The result is a coffee bean prized by enthusiasts the world over, and retailing for roughly $700 US per kilogram.
And that’s not all. One bright engineer, Peter Janicki has figured out how to turn poo — which is about 75% H2O anyways — into drinking water.
Poo can tell us fascinating facts about our past
The caves of El Salt in southern Spain are one of the greatest archeological sites in the world. These rock shelters were home to Neanderthals — our evolutionary ancestors — nearly 60,000 years ago. During a recent excavation Ainara Sistiaga, a geo-archeologist from MIT uncovered an unexpected treasure —five pieces of 50,000-year-old fossilized feces — some of the oldest in the world. Back in the lab, she analyzed the samples and was the first to discover that contrary to popular belief, Neanderthals were omnivores just like us. Her discovery debunks the long-held theory that Neanderthals became extinct because of their meat-dominated diet.