Farting while eating natto can be caused by physiological factors or gastrointestinal diseases. 1. Physiological factors: Natto itself is a gas-producing food, and eating natto can promote gastrointestinal peristalsis, which helps in the digestion and absorption of food. When intestinal peristalsis is accelerated, the phenomenon of farting will occur. Especially when eating too much natto, farting is more likely to occur. 2. Gastrointestinal diseases: If you suffer from gastroenteritis, ulcerative colitis and other diseases, the mucous membrane of the gastrointestinal tract will be stimulated, and then gastrointestinal flatulence will occur. If you eat natto during the period of illness, it will easily cause farting symptoms. If you have farted while eating natto and are experiencing other discomforts, it is recommended that you go to the hospital in a timely manner.