FUT4 and infection: The major OMPs essential for H. pylori colonization and infection in gastric mucosa mainly include the blood group antigen-binding adhesion (BabA) that binds to host cell surface Lewis b glycan (Leb) and the sialic acid-binding adherence (SabA) that binds to the sialyated Lewis x (sLex) and Lewis a (sLea)38.