British pet food brand THE PACK and German biotechnology startup MicroHarvest have announced the launch of “Gut Bites,” the UK’s first microbial protein dog treats.
The treats are made by fermenting ingredients from “agricultural side-streams,” which are the plant-based byproducts and waste products generated by growing, harvesting, and processing food for human consumption. This means producing Gut Bites requires no additional farmland, pesticides, or fertilizers.
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According to THE PACK and MicroHarvest, the pet food industry uses an area of land twice the size of the UK to produce dry food for cats and dogs, generating 106 million tonnes of CO2 per year. The meat industry causes at least 20 percent of anthropogenic emissions, and dogs and cats eat at least 20 percent of all meat and fish.
The companies claim that the upcycled ingredients used in Gut Bites mean the product’s footprint is more than 90 percent lower than beef and “significantly” lower than comparable plant proteins. They say that the proprietary microbial protein and allergen-friendly recipe also make Gut Bites suitable for companion animals “with sensitivities and intolerances.”
“Our community of dog owners often tells us they struggle with picky eaters and pets with allergies or sensitive stomachs,” said Damien Clarkson, the managing director of Prefera Pet Food UK, which operates THE PACK. “Gut Bites is our answer: a delicious, functional treat that’s also allergy-friendly.”
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Microbial protein in dog food is a ‘game changer’

In 2024, MicroHarvest partnered with Germany’s VEGDOG to launch a similar plant-based dog treat made from the same upcycled, fermented microbial proteins.
A 2024 consumer study conducted with a Wageningen University Master’s program found that 77.2 percent of those with dogs in the UK and Germany would buy microbial protein treats, while 78.4 percent would consider a complete dog food.
During palatability tests for Gut Bites, the companies found that even selective small dogs consistently preferred food made with MicroHarvest protein. Fifty-eight percent chose microbial protein-based food over the alternative, and ate 44 percent more.
“We’ve always been open to next-generation ingredients and MicroHarvest’s microbial protein stood out as a game-changer,” said Clarkson. “This launch demonstrates our commitment to bringing UK pet parents products that are innovative, healthy, and sustainable.”
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