HP and Helicobacter pylori infectious disease: Finally, a dose–response relationship between Helicobacter pylori (Hp) infection and HG has been demonstrated, and garlic and onions, which have antibiotic properties and are rich in allicin, are effective against Gram-negative bacteria, such as Hp [47], and we hypothesized that onion vegetables may alleviate the symptoms of HG by inhibiting Hp infection and have a protective effect against HG.