In the present circumstances, many studies have been carried out on the aquaculture, respiratory physiology, and lipid metabolism of the loach. Studies have shown that the use of phenolic compounds as feed additives for farmed fish provides many beneficial effects on fish health and performance by strengthening the immune system and stimulating appetite, and improving intestinal digestion and mucosal function, morphology, and integrity, as well as gut microbial community composition. The fermented soybean dregs contain abundant active components, such as phenolic compounds. As a consequence, we put forward a bold hypothesis: using soybean fermentative powder to feed loach can not only make rational use of resources but also solve the problem of healthy growth of loach due to microbial infection and other environmental factors.