Shiitake mushrooms are not recommended to be eaten after being left for a longer period of time. Shiitake mushrooms have certain nutritional value, containing protein, vitamins, minerals and other nutrients. After being left for a long time, it is easy to cause the reproduction of bacteria and fungi on the surface, and when it comes into contact with the oxygen and moisture in the air, the bacteria and fungi in the environment adhere to it, and if the ambient temperature is still high at this time, the shiitake mushrooms are more likely to deteriorate. Shiitake mushrooms may produce, for example, Aspergillus flavus after a long period of time, which can lead to organ damage and cancer when eaten accidentally. Therefore, it is not recommended to eat shiitake mushrooms when they have been stored for a long time, and they should be discarded in time. In your daily life, you should pay attention to the preservation time of food and eat more fresh vegetables.