Physicians used to believe that stomach ulcers were caused by excessive acid but recent studies have found evidence that the presence of a bacterium called Helicobacter pylori is responsible for most ulcers. It is spread by fecal oral contact. One specific molecule of the H. pylori is VacA. It causes large spheres called vacuoles to appear in the cells. It is still unclear about how the VacA's are involved with causing ulcers. A technique called deep-etch electron microscopy helped investigators analyze the structure of the VacA . They have found the structure to be a flower like shape consisting of petals joining to a circular ring. It has two interlocked six petal rings. They observed that when it was in an acidic solution it breaks up into many teardrop shaped sub units.
This usually infects about 20% of people under 40 years and 50% of those above the age of 60 years. It is very uncommon in young children but a majority of people in the world are infected. Most infected people have no symptoms, however. There has been a 50% decrease in the amount of people infected since 1968.
There has been a lot of controversy about the microbe H. pylori having benefits as well. Martin Blaster, who has been studying H. pylori for many years, suggests H. pylori might also reduce the risk of cancer.
REFERENCE:
Christensen, Damaris. Science News. Volume 156 No. 15
