A Japanese company called Metagen Therapeutics has opened a "Stool Donation Room" in Tsuruoka, Yamagata, where people can earn 5,000 yen per donation of stool samples. This initiative supports research into gut microbiomes and the development of new medicines.

However, only 5–10% of samples are considered suitable for research, so not everyone's donation will be accepted. Healthy individuals between the ages of 18 and 65 must apply online and go through a health screening process. If selected, a person could earn up to 30,000 yen per year through regular donations.