This Berkeley-based startup wants to feed your dog fungus

Henry considers a Wild Earth dog treat made with koji fungus. Photo: Stuart Luman

Berkeley biotech startup Wild Earth is aiming to shake up the $30 billion pet food industry by serving dogs and cats a diet of fungus and lab-grown mouse meat.

The products, according to Wild Earth co-founder Ryan Bethencourt, are environmentally friendlier, safer, higher quality and more nutritious than conventional pet foods.

“Most people think the meat in pet food is the same as what we eat, but it’s really not,” Bethencourt said while sitting in his company’s unfinished 4,000-square-foot West Berkeley lab and office space, complete with microscopes, incubators and a 100-liter bioreactor used to grow a fungus called koji, the basis for the company’s first available dog treat product. Much of the meat used in pet food is actually “meal” made from ground-up carcasses that would otherwise be discarded.

And it’s not just low-quality ingredients in kibble, he cautioned. Mass-produced, animal-based pet food can also be dangerous. As an example, he pointed to last year’s FDA recall of several major pet food brands after they were found to contain pentobarbital, a powerful barbiturate used to euthanize animals.


Koji is grown in a bioreactor at Wild Earth’s lab in West Berkeley. Photo: Wild Earth

Bethencourt is no newcomer to biotech. He is a co-founder of San Francisco-based biotech incubator IndieBio and has invested in more than 70 biotech companies — including Bay Area-based “food tech” businesses such as Clara Foods, Finless Foods and Memphis Meats, which all seek to create innovative alternatives to traditional meat or animal-produced foods. “Berkeley is an ideal place to start this company with its mixture of foodie culture and science,” he said. “I don’t know a place, even San Francisco, that would be better.”

Bethencourt has advanced degrees in biotech-related disciplines, is a long-time vegan and has a deep belief that science can reinvent what he and his co-founders say is an environmentally unsustainable food system that is ravaging the planet. He’s also a dog lover; he fosters dogs for Oakland-based Rocket Dog Rescue, his most recent was a one-year-old yellow labrador named Justin Bieber.

The company’s name comes from the founders’ vision of a world no longer dependent on industrial-scale farming, where large swathes of land now dedicated to agriculture would be allowed to return to their wild state.

“We want to remove factory farming from our food, full stop,” he said. “IndieBio was really the exploration of future foods for humans. Wild Earth is the exploration and development of future foods for our pets.”

According to Ron Shigeta, another Wild Earth co-founder and its chief science officer, the company is on the cutting-edge of a new food movement. “Everybody is starting to understand,” he said of the need to find alternatives to the existing food system. “Dog food represents a bellwether for foods of the future. Pet food is in a special place right now and we saw a huge opportunity for impact here.”

Wild Earth dog treats are made without animal products; they get their nutrients from ingredients like koji, oat flour and pumpkin and are flavored with peanut butter. Photo: Wild Earth

It’s all about the koji

Wild Earth’s first product, which it started selling on its website last October and now at several San Francisco and Oakland pet stores, was a peanut-butter–flavored dog treat made from koji. Koji is a mold that has been used for centuries in countries such as Japan to produce the savory umami flavor found in miso soup, soy sauce, bean pastes, sake and other foods.

The human — and canine — mouth and tongue has five flavor receptors that can taste for sweet, sour, bitter, salt and umami, a savory flavor that is naturally occuring in mushrooms, certain cheeses, tomatoes and seaweed.


Inspiration for using koji as the basis for dog treats came from Shigeta, who was using the fungus to engineer interesting sauces, marinades and flavors for his own consumption, according to Bethencourt. The a-ha moment came when the two began thinking about how they could create a high-protein alternative food for pets that would offer excellent nutrition, reduce the impact of food production on the environment and taste good. Koji satisfied their demands and was eagerly eaten by their pets.

According to the company, koji provides a high-protein, easily digestible food with 10 amino acids, omega fatty acids and healthy enzymes without any additive sugars, grains or animal ingredients. To make the treats, the koji is combined with oat flour, flaxseed, pumpkin and peanut butter. Since the treats are sourced from a lab rather than a slaughterhouse, there’s much less chance for contamination and production is much less environmentally intensive than industrial farming.

The next product the company hopes to sell is a mouse-meat cat treat, which won’t need mice to be slaughtered to produce. Instead, cells from mice will be cultured and grown, creating meat in the lab. Unlike dogs, which are omnivores and technically don’t need meat to survive, cats are “obligate carnivores” and depend on meat for several amino acids that they can’t produce on their own.

“We’re starting first with cultured fungus products and will move into cultured meats over time,” said Bethencourt. “This will be cruelty-free meat.”

A wild future

Wild Earth has garnered significant investor and media attention. So far, venture capitalists have invested more than $4 million in the company, according to Bethencourt. While some of the cash has come from dedicated vegan and anti-factory farming groups, Wild Earth also received $450,000 from Peter Thiel, the outspoken serial investor, early Facebook investor and director, and co-founder and former CEO of PayPal. Wild Earth also received $200,000 from industry-leader Mars Petcare, which owns Pedigree, IAMS and other major — and certainly non-vegan — brands of traditional pet food.

Wild Earth’s future plans include a complete koji-based dog food that may be available for purchase by mid-year and koji-based cat treats for sale later in 2019. Bethencourt predicts that lab-grown meat treats and meals wouldn’t be approved by the FDA until 2020 due to regulatory issues.


Wild Earth’s longer-term plan is for a completely personalized diet for pets based on the DNA analysis of each animal’s microbiome, the unique combination of bacteria and microbes that inhabit the gut. Such knowledge would allow Wild Earth to create kibble that is perfectly tailored to a pet’s health needs, allergies and other requirements. The company has already started testing the microbiomes of staff and their pets in anticipation of this future offering. Bethencourt hopes that Wild Earth could sell such a personalized product within five years.

Even further in the future, Bethencourt imagines humanity’s descendants living in space colonies and surviving primarily on fungus-based foods. But before we get there we’ll have to figure out a way to feed the 10 billion people anticipated to be inhabiting Earth by 2050 and their billions of pets.

Henry serves as a guinea pig for tasting Wild Earth’s koji-laden dog treats. Photo: Stuart Luman

The taste test

It’s fine to discuss how fungus could save the world in theory, but what do real pets and their owners — or pet parents, as Bethencourt calls them — think about it?

In the name of journalism, I volunteered Henry, my food-obsessed terrier-mix, and myself to eat some peanut butter-flavored koji dog treats. A first whiff from the blue and white Wild Earth bag elicited strong notes of peanut butter. Breaking the inch-by-inch treat in half, I nibbled and offered the other half to Henry who sat at military-style attention in my kitchen as I rolled the treat around my mouth to get the full flavor profile.

Although the peanut butter smell was strong, the treat itself had a muted taste and a hard, dry texture. My concerns didn’t appear to bother Henry, who gobbled treat after treat with abandon while performing a bevy of sits, stays and paw shakes. His enthusiasm for Wild Earth’s offering was evident, although to be honest, I haven’t found him to have the most discerning palate.

In the interest of getting more than Henry’s and my reactions, I later headed to Berkeley’s Ohlone Dog Park near the corner of Hearst and Martin Luther King, Jr., to gauge how other humans might feel about feeding fungi to their best friends.

The general conclusion of the three people I spoke with was doubt and then later some wary interest.

“Why wouldn’t I just feed him meat?” asked Hadar Meiri, a 37-year-old from Oakland, who herself eats meat and was at the park with her two-year-old corgi-mix, Dobby, who eats an entirely raw chicken- and vegetable-based diet. “Dogs in the wild don’t eat fungus.”

Geoffrey O’Brien of Berkeley was more enthusiastic. “I love the idea of meat substitutes and lab-grown alternatives,” said the 49-year-old, who once was a vegetarian but gave it up as he got older and felt he needed the extra nutrition. He feeds his three-and-a-half-year-old Doberman-shepherd mix, Friend, a high-quality, meat-based kibble and a raw food topper as a garnish. He thinks dogs should eat what “they were designed for,” but added that he was “open to hearing why or how meat substitutes are not disadvantageous.”

Oakland-resident Susan Hoskins, an avid vegetarian, feeds her two-and-a-half-year-old black labrador, Bear, a freeze-dried mixture of lamb, beef and chicken because she feels that dogs need meat to be healthy. “I don’t want animals killed for the consumption of people or other animals,” said the 67-year-old, but she demurred when asked if she’d feed Bear a fungus-based or non-naturally sourced meat-based diet. “You’re talking to someone who is really educated, but unless someone came and gave me the health rundown on its benefits, I don’t think so. How can fungus be good?”