Normal consumption of papain or food processed by papain will not irritate the stomach, but overdose will cause some stomach irritation.
Papain is a sulfhydryl protein hydrolase extracted from papaya with esterase activity that can hydrolyze proteins, polypeptide chains, and esters. Consumption of normal doses and uses of papain can help gastrointestinal digestion and will not cause gastric irritation. In addition, papain is a polypeptide consisting of 212 amino acid residues, which can also be hydrolyzed by pepsin when it enters the stomach and will not irritate the gastric mucosa.
It should be noted that papain may cause gastric mucosal irritation if consumed other than for medicinal purposes or in excessive amounts. Some people are allergic to papain and consumption of papain may cause hypersensitivity reactions, so such people should not consume it.
If papain is used in the treatment of disease, it should be used under the guidance of a doctor, do not use it on your own, and if you feel unwell, please consult a doctor immediately to avoid adverse consequences.