First of all, pure coarse grains have a rough texture and a single taste, which is difficult to swallow. Therefore, few people can insist on eating only original coarse grains in their daily diet. Secondly, if people with delicate gastrointestinal function eat coarse grains every day, it is easy to cause abdominal distension, abdominal distension and other discomfort symptoms, which is easy to cause indigestion.