Evolutionary history of Helicobacter pylori
Marina Espínola & Teresa Alarcón
Helicobacter pylori is a bacteria associated to humans from immemorial times, being adapted to him. They have evolved together from at least 50,000 years and probably during their all history. H. pylori show a great genetic diversity due to its big variation ability in response to different stimulus, such as the immune human response and stomach environmental factors. The genetic diversity among H. pylori strains decrease with the distance from Africa, in the same way that genetic diversity decrease among humans. The Multilocus sequence typing (MLST) analysis allows grouping H. pylori strains in different types coinciding with the geographic association: hpEurope, hpEastAsia, hpAfrica1, hpAfrica2, hpAsia2, hpNEAfrica, y hpSahul.
It is not known how is going to evolve from now, taking into account that H. pylori infection is decreasing due to the increase in hygienic conditions and the antimicrobial treatments. It has been described an association between absence of H. pylori infection and gastroesophageal reflux disease, and an increase in obesity and related diseases and atopic and allergic diseases, including asthma.