Why H. pylori is not destroyed by stomach acid?

Helicobacter pylori has evolved several mechanisms to survive in the harsh acidic environment of the stomach:

Urease enzyme: H. pylori produces urease, an enzyme that converts urea into ammonia. This creates a localized alkaline environment around the bacteria, neutralizing the surrounding stomach acid.

Flagella: H. pylori is highly motile due to the presence of multiple flagella. This enables the bacteria to move and penetrate the mucus layer that lines the stomach, providing some protection from the acidic environment.

Mucus colonization: H. pylori can adhere to and colonize the mucus layer that covers the stomach lining. The mucus layer acts as a physical barrier, further shielding the bacteria from direct contact with stomach acid.

Acid resistance proteins: H. pylori produces various acid resistance proteins that help it survive in low pH conditions. These proteins protect the bacterial cell wall and cellular components from damage caused by stomach acid.

Efflux pumps: H. pylori possesses efflux pumps that actively expel protons (H+) from the bacterial cell. This helps the bacteria to maintain a near-neutral intracellular pH, counteracting the acidic external environment.

These mechanisms allow H. pylori to withstand the acidic conditions of the stomach and establish a persistent infection. However, it's worth noting that some H. pylori strains may be more resistant to stomach acid than others, contributing to their ability to colonize and cause disease in certain individuals.