The study was conducted at seven locations in six countries - Mexico, Nicaragua, Honduras, Costa Rica, Colombia, and Chile.

In a research paper published in The Lancet, Greenberg and his colleagues explain that the responses to the different drug combinations might be explained by regional variations in resistance that H. pylori has developed to the specific antibiotics and other medicines in each combination regimen.

More than 87 percent of those in the three-drug group who took their medicine were cured of their infection, a success rate that suggests the possibility of eradicating H. pylori. But researcher Greenberg says it's not a simple decision.

"I think, although we were positive in saying we think it's feasible to eradicate [H. pylori], we ourselves are undecided as to whether and how an eradication program should be implemented."

Because H. pylori is more common in developing countries, eradication might make more sense in those areas, although Greenberg and his colleagues take no position on whether it should be done.

In a commentary published with Greenberg's paper, a trio of Brazilian experts argue against mass eradication for several reasons, including the fear that the widespread use of antibiotics could prompt drug-resistant mutations not only of H. pylori but of other pathogens, too.