Senior researcher Dr. Nina Salama and team — in collaboration with researchers from Zhengzhou University in China — collected and analyzed samples from stool and from stomach endoscopies from 49 participants.
The scientists were aiming to see which kinds of H. pylori would be associated with stomach cancer.
Through their analysis, they identified one strain that stood out from the rest: H. pylori with a variant of the cytoxin-associated gene A — namely, the EPIYA D variant. Of the study participants with this strain, 91 percent had a diagnosis of stomach cancer.
“We’ve known the H. pylori bacterium has a strong correlation to stomach cancer, but it’s been difficult to pinpoint why certain patients, especially in areas like Northeast Asia, are more susceptible to stomach cancer,” notes Dr. Salama.
“While [the recent study is] preliminary in nature, these results could be the first step towards identifying the highest-risk groups and improving screening and treatment plans,” she adds.
‘A clear target to develop vaccines’
This information, Dr. Salama believes, could provide specialists with a new therapeutic target, thereby allowing them to develop better defenses against stomach cancer.
“Unfortunately, infections like H. pylori directly or indirectly, cause up to 20 percent of cancers worldwide. But knowing the cause gives us a clear target to develop vaccines for prevention or tools to better recognize risk.”
Dr. Nina Salama
At the same time, however, the researchers admit that their study was small and had a limited number of participants. This means that they cannot yet extend their findings to the general population.
In the future, the scientists would like to conduct more studies investigating the mechanisms through which H. pylori may impact cancer risk.
“Further studies,” the authors conclude, “will need to be done to investigate the factors that contribute to the observed higher H. pylori load in the stool among gastric cancer subjects compared to noncancer subjects despite a similar H. pylori load in the stomach.”