A study published on 23 September 2026 in the journal PLOS One showed that cats and dogs in a short-term test prefer dry food with a 10 percent content of microbial protein to conventional food based on animal protein. The work was carried out by researchers Ally Motta de Matos and A.L.B. Cruz from the European company MicroHarvest, which specialises in producing protein by fermentation, and the trials were funded by the company itself.
The experiment involved 30 dogs and 30 cats, which were fed at home using the two-bowl method over four meals in two days. One bowl contained standard food imitating a commercial diet based on fish and rice, the second — an almost identical composition in which microbial protein completely replaced fishmeal and partially replaced poultry. The owners did not know which bowl contained which food. Statistical analysis confirmed a significant preference: dogs ate 72 percent of the food with microbial protein versus 50 percent of the conventional food, cats — 51 percent versus 34 percent. Animals of both species more often approached and began eating from the bowl with the new ingredient.
Microbial protein is obtained through the fermentation of microorganisms, which makes it possible to obtain high-quality protein with a complete set of amino acids. In the study, it replaced traditional sources — fishmeal and part of the poultry — while preserving the macronutrient balance. The authors note that the preference manifested itself despite the replacement of familiar components, and emphasise: this is an encouraging start for understanding how microbial proteins are perceived by animals not only from the point of view of nutrition, but also of taste.
The results have practical significance for pet food manufacturers: microbial protein could become a sustainable alternative that reduces dependence on fish resources and livestock farming. However, the authors state outright that the study covered only a short period, so long-term attractiveness, tolerability and effects on health require additional trials.
In a broader context, the work fits into the industry's growing interest in alternative sources of protein for pets, where, alongside insects and plant components, microbial technologies offer a new path to sustainable nutrition without compromising the taste preferences of pets.
The short test showed that even with partial replacement of animal protein, the microbial variant proved more attractive to cats and dogs.
