Removes the 1-phosphate group from tetra- and probably hexaacylated lipid A species (PubMed:16740959). Absence of the 1-phosphate group renders the bacteria partially resistant to host-derived cationic antimicrobial peptides (CAMP), allowing it to camouflage itself from the host innate immune response, and plays a role in the long-term colonization of the host's stomach (PubMed:22216004). Bacterial outer membrane biogenesis; LPS lipid A biosynthesis. Accumulation of 1-phosphate tetraacylated lipid A, unlike strain 26695 no hexaacylated lipid A is detected (PubMed:16740959, PubMed:22216004). 16-fold to 25-fold decrease in resistance to CAMP polymyxin B (PMB) (PubMed:16740959, PubMed:22216004). Increased cell-surface binding of CAMP, 2-fold decrease in resistance to endogenous antibacterial peptide Hp (rplA). Lipopolysaccharide (LPS) from this strain induces the human innate immune response via Toll-like receptor 4 (TLR4) 2-fold in cultured cells (similar effects are seen with mouse cells, has no effect on TLR2-mediated induction). No changes in O-antigen or motility. Decreased ability to colonize C57BL/6J mouse stomachs (using mouse-adapted H.pylori strains B128 and X47). A double lpxE-lpxF mutant accumulates 1-, 4'-bisphosphate hexaacylated lipid A, has 1000-fold decrease in resistance to PMB (a similar reduction in resistance is seen for other human-derived CAMPs), a 70-fold decrease in resistance to endogenous antibacterial peptide Hp, induces the innate immune response via TLR4 10-fold, loss of colonization of C57BL/6J mouse stomachs (strains B128 and X47) (PubMed:22216004). In this organism most lipid A is tetraacylated without a phosphate group at the 4'-position and a phosphoethanolamine residue at the 1-position. Belongs to the lipid A LpxE 1-phosphatase family.