Eating with a syphilis patient is not contagious. Syphilis is a chronic infectious disease caused by infection with the syphilis spirochete and is transmitted mainly through sexual contact, mother-to-child transmission and blood transmission. About 95% of patients are infected through sexual contact, transmitted by tiny breaks in the skin mucosa. In addition, syphilis spirochetes can be transmitted from mother to fetus through the placenta and umbilical vein. Blood from syphilis patients that has been frozen for less than three days is still contagious, and infection can occur by importing such blood. In short, syphilis is not transmitted through the digestive tract when eating with a syphilis patient.