Protein digestibility is affected by the type of protein itself, protein intake, the body’s physical condition and the protein environment. Analyze as follows: 1. The kind of protein itself: the composition of animal protein is similar to that of human body protein, and the surface of plant protein has cellulose, which is not conducive to protein decomposition, so the nutritional value and digestibility of animal protein is relatively higher than that of plant protein. 2. Protein intake: due to the body’s protease number is a certain amount, when a large amount of protein intake, digestive enzymes can not fully digest the protein, resulting in a decline in digestibility. Therefore, the diet in daily life should pay attention to the reasonable combination of protein, otherwise it may cause indigestion, allergies and other effects. 3. Human body condition: when the body is in high fever, cold, protease activity is far below the normal level, when the body ingests protein, the enzyme activity can not give full play to, at this time, the digestive rate decreases. When hyperthyroidism, glucocorticoids increase, will increase protein consumption, inhibit protein synthesis, at this time, protein digestibility. 4. Protein environment: when the protein is in the gastric acid environment, pepsin can give full play to the enzyme activity to decompose, digest and absorb the protein, when too acidic or too alkaline, the enzyme activity decreases, protein digestibility decreases. If the patient has uncomfortable symptoms, it is recommended to actively go to the hospital for a clear diagnosis.