In general, a negative IgM IgG positive for H. pylori suggests that the patient has had a previous H. pylori infection. IgM and IgG are both abbreviations for immunoglobulins in serum, a class of proteins with antibody activity in human serum and body fluids, with antibacterial and antiviral effects. They can kill or dissolve pathogenic microorganisms in a synergistic manner and are important components of the body’s defense against disease. IgG is the main immunoglobulin in serum and body fluids, accounting for about 70% to 75% of the total immunoglobulin in the blood, and it has an important role in pooling complement, enhancing phagocytosis of pathogenic microorganisms by immune cells, and neutralizing bacterial toxins, etc, and it can effectively fight infections.IgG positivity is usually indicative of the presence of a previous infection in the patient. IgM is the protein with the largest molecular weight among immunoglobulins, also known as macroglobulin, accounting for about 10% of the total serum immunoglobulins, and it is the earliest antibody to be produced in the course of an individual’s development, so IgM negativity can rule out the existence of a recent infection in the patient. In summary, H. pylori IgM negative IgG positive suggests that there has been a previous H. pylori infection, and the body has produced antibodies. Consult your physician for specific test results.