Novel pet food products have been marketed based on ingredients obtained through fermentation. In the USA, Wild Earth pet food products were originally founded on the inclusion of a fungi-based protein source. This protein source is referred to as a clean protein source due to it being produced by fungi. Gregory D. Sunvold at Sunvold Technology reviews how fungi-based protein sources not only have a strong sustainability message, but also have myriad probiotic-related health benefits that make fermented foods appealing for consumption.