WANTED: Poop donors in Yamagata for colon bacteria study

by KOJI SHIMIZU
June 10, 2025

This 10-course “shojin” vegetarian meal served at Mount Haguro Sanrojo Saikan, a shrine lodging at one of the Three Sacred Mountains of Dewa in Tsuruoka, Yamagata Prefecture, on Sept. 18, 2024, contains dishes wherein local crop varieties are used, such as Tonojima cucumbers boiled down in soy sauce, far right in the middle row, and taro stalks dressed with miso and ground sesame, far right in the bottom row. (Koji Shimizu photos


TSURUOKA, JAPAN -- Shonai residents enjoy an opulent culinary culture in the region that has taken root in helping them lead healthier lifestyles.

Many residents of the area are ingesting a broad variety of dietary fibers, which helps increase the diversity of intestinal bacteria, making their stool samples vital resources for researchers.

A facility designed exclusively for stool donations was set up recently in this northeastern city, by a business venture with roots in Juntendo University and other institutions.

The collection center is calling for donors who may have a useful flora of intestinal bacteria in their bowels. If donors qualify, they will get paid for their troubles.

The poop to be donated at the facility in Tsuruoka, Yamagata Prefecture, the first of the sort in Japan, will be used to develop drugs for treating diseases including ulcerative colitis, which is designated as intractable.

The Tsuruoka stool donation room, which opened April 24 in a science park in the city, is operated by Metagen Therapeutics Inc.

The Tsuruoka-based startup has its origins in Juntendo University, Keio University and the Institute of Science Tokyo.

“The help of citizens matters more than anything else for making sure that intestinal bacteria that are rooted in Tsuruoka’s culinary culture will be delivered to the rest of the world,” Metagen Therapeutics CEO Taku Nakahara told an opening ceremony on April 24. “We hope to be working with you all to save patients across the globe.”

The collection facility has three restrooms, designed specifically for stool donations and with no water flush functions, and a lounge area, where donors can make themselves at home until they are ready to move their bowels.

Human intestinal bacterial flora is believed to contain about 1,000 species, which work, in keeping an exquisite balance, to maintain the host’s health, including by promoting digestion and defecation and by adjusting immunity.

Overuse of antibacterial agents (antibiotics) and an excessive intake of animal protein and fat can cause a loss of healthy intestinal bacteria and give rise to various diseases, Metagen Therapeutics officials said.

‘SUPERB’ INTESTINAL FLORA

Therapies that involve transplanting healthy intestinal bacteria into patients to improve their intestinal environment are currently being studied in Japan.

Metagen Therapeutics has been working on the research and development of drugs that are made from feces.

A search for healthy intestinal florae led the company’s officials to the Shonai area, including Tsuruoka, in the northwest of Yamagata Prefecture.

The foods eaten here include the “shojin” vegetarian cuisine of the Three Sacred Mountains of Dewa, which draws on edible wild plants, mushrooms and other food ingredients of the season, as well as the use of locally available crop varieties.

Hopes for the availability of healthy and “superb” intestinal florae prompted the selection of the Shonai area.

The local community has been cooperative toward the project. A local restaurant, for example, has prepared, on a trial basis, dishes that are friendly to the intestinal flora.

Residents also responded positively during an explanatory meeting held in advance, officials of the startup said.

The Tsuruoka stool donation room is the first facility in Japan that is specially designed for the purpose, even though Juntendo University Hospital in Tokyo had already been accepting stool donations, the company officials added.

5,000 YEN PER DONATION

Eligible for stool donations are residents of the Shonai area aged between 18 and 65.

Prospective donors have to sign up on a Web page before they take an online health checkup and undergo an interview with a doctor, a blood test and a stool test at the Tsuruoka Municipal Shonai Hospital.

Those who qualify are registered as donors and are asked to visit the facility regularly. They are entitled to receive up to 5,000 yen ($34) in “cooperation money” per stool donation.

The Metagen Therapeutics officials said they have set the target of having somewhere between several dozen and 100 registered donors by year-end.

Intestinal bacteria will be extracted from the donated poop and processed for preservation at dedicated equipment before being shipped to a drug manufacturing facility in Kawasaki, Kanagawa Prefecture, to make medicines.

Metagen Therapeutics is currently engaged in the research and development of poop-derived drugs for treating ulcerative colitis, gastrointestinal cancer and Parkinson’s disease.

The company is planning to start clinical tests for an ulcerative colitis drug in Japan and the United States in 2026, and is hoping to have the drug approved for use and released for sale in 2032.

The world’s first poop-derived preparation was approved for use in Australia in 2022. The United States has also approved similar drugs.