A small amount of qualified stinky tofu is generally not significantly harmful, but a large amount of intake can increase the risk of cancer, and stinky tofu contaminated with stray bacteria can also cause food poisoning. Stinky tofu is fermented by rotting bacteria to produce hydrogen sulfide, amines and ammonia, which become the source of its odor, and the remaining proteins that have not been completely decomposed by the rotting bacteria become free amino acids, which become the source of its fresh taste. In the process of stinky tofu, it is very easy to produce harmful substances amines, which combine with nitrite to produce nitrosamine, which is actually a strong carcinogen that can increase the incidence of esophageal cancer, stomach cancer and other cancers. Meanwhile, if the temperature, humidity and other conditions are not properly controlled during the fermentation of stinky tofu, it is easy to be contaminated by bacteria, including Staphylococcus aureus, Salmonella and Clostridium botulinum, etc., which can multiply in stinky tofu, and if the amount of them increases to a certain level, it can cause food poisoning, which manifests itself as nausea, vomiting, dizziness, diarrhea and other symptoms. Therefore, in real life, it is recommended to eat stinky tofu in moderation, not excessive consumption, and the frequency should not be too large, or to fresh unprocessed food, so as to ensure the health and safety of the human body.