With the recent news that precious metals have been found in human excrement, people around the world have been asking themselves: are we flushing down a goldmine every time we go to the bathroom?

The answer is probably not a goldmine but at least enough to pad your pockets with a little extra cash.

Since 2013, the nonprofit Massachusetts-based group, OpenBiome has been processing and shipping loads of human excrement all over the country. It offers to pay up to $13,000 a year to obtain a steady stream of fecal matter that can be used to treat people suffering from a debilitating and even fatal intestinal bacteria called C. difficile. Although antibiotics help, the bacteria comes back after the treatment is stopped, leaving those who suffer from it housebound.

Doctors have found that the solution to this is introducing healthy fecal matter into the gut of the patient through endoscopy, nasal tubes or swallowed capsules so that the bacteria can be eliminated permanently. Some of those who suffer from the condition have even resorted to treating themselves with fecal matter from friends and family members.

According to Techtimes.com, the company sends thoroughly screened frozen stool samples to around 200 treatment centers around the country, but finding enough donors to keep the operation going has been difficult.

For this reason, it is willing to pay a good amount of money for your poop: $40 per sample, plus a $50 bonus for donors willing to contribute poop five days a week. Add that up and it amounts to $13,000 a year.

The catch is that donors must go in person to donate their feces at the company's headquarters in Medford, so it limits the offer to those who live or work near the area.

Besides this, donors must first pass 27 blood and stool tests to qualify. They must have a body mass index less than 30, be in very good health, and be between the ages of 18 and 50. The requirements are so stringent that only 4 percent of potential donors actually pass all the tests. Every 60 days, donors are screened to make sure that their excrement is up to standards.

"It's harder to become a donor than it is to get into MIT," jokes OpenBiome's co-founder Mark Smith, who got his own PhD in microbiology there.

Still, most donors are happy not only to earn easy cash, but to think that they are potentially saving lives.

"Everyone thinks it's great that they're making money doing such an easy thing, but they also love to hear us say, 'Look, your poop just helped this lady who's been sick for nine years go to her daughter's graduation,'" says OpenBiome co-founder Carolyn Edelstein.