Stomach cancer is the third leading cause of cancer death globally. Rates for stomach cancer are 3-4 times higher among the Navajo Nation compared to the non-Hispanic white population in Arizona. Helicobacter pylori (H. pylori) plays a role in the healthy human gut, but it is also associated with multiple chronic diseases, including stomach cancer. A multi-year research program, conducted in partnership with Northern Arizona University through the Partnership for Native American Cancer Prevention, seeks to estimate the prevalence of H. pylori among Native Americans. The study in 2018 reported a 56.4% prevalence of H. pylori within participants from three Navajo chapters, with 72% of households having at least one infected person. This research program was expanded to continue the study through other regions of Navajo Nation. Together these studies will test hypotheses that the high H. pylori prevalence in Navajo communities correlates with environmental and behavioral factors as well as diagnostic delays and to determine the genotypes of H. pylori in Native Americans in Northern Arizona and antibiotic resistance to therapies.