Salt, soup, and stomach health: how diet shapes H. pylori infection risk in the Navajo Nation

Helicobacter pylori (H. pylori) is one of the most common bacterial infections in the world, yet its burden isn’t shared equally. Dr. Dornell Pete, an assistant professor at Public Health Sciences Division at Fred Hutchinson Cancer Center and member of the Navajo Nation, explained that “the American Indian/Alaska Native population experiences high incidence and mortality rates of stomach cancer.” In her earlier work, she found that 58% of adults in the Navajo Nation, one of the largest tribal nations in the United States, are chronically infected with H. pylori. “Little is known about modifiable risk factors for H. pylori in the Navajo Nation, particularly diet risk factors,” Dr. Pete added.

To better understand this connection, Dr. Pete and her collaborators at Fred Hutchinson Cancer Center and the University of Washington decided to look closely at how dietary patterns relate to H. pylori infection. While researchers have long known that high-sodium and processed foods can worsen H. pylori infections, no one had studied this relationship in an Indigenous community. “Our analysis focuses on American Indian adults in the Navajo Nation, a population with a high prevalence of H. pylori but very limited dietary research,” Dr. Pete emphasized. “It also addresses a major data gap in evaluating the relationship between diet and H. pylori infection, which has not been previously examined in this group.”

Between 2020 and 2022, Pete’s team worked with 93 Navajo adults, most of them women, to explore what people were eating and whether those patterns might relate to H. pylori infection. Participants filled out two questionnaires: one standard food frequency survey used in cancer research, and another — the Navajo Food Questionnaire — that Pete’s team designed with local input to include traditional foods like frybread, blue corn mush, mutton stew, and Navajo tacos. Each participant also provided a stool sample, which was analyzed in Fred Hutch’s Salama Lab using a highly sensitive test called droplet digital PCR to detect H. pylori DNA.

In their new study published in Nutrition and Cancer, they found three major dietary patterns in the community. One looked a lot like what public health researchers call a “Western” pattern, characterized by processed meats, refined grains, sweets, and salty snacks. Another emphasized fruits and vegetables. The third — and the most surprising — was labeled “Soups and Mixed Dishes.” It included foods like stews, ramen, spaghetti, burritos, enchiladas, and other combination meals that blend meats, grains, and sauces.

It was this last pattern that caught Pete’s attention. People who ate more of these soup-and-stew-style dishes were nearly five times more likely to test positive for H. pylori than those who ate them the least, even after accounting for age, sex, and total calories. “We found that participants with a high score for a diet of Soups and Mixed Dishes had higher odds of H. pylori infection,” Pete says. “This positive association may be linked to the sodium content of foods in this diet pattern, such as spaghetti, pasta, Asian noodles, burritos, enchiladas, and tribal stews.”

That finding fits with what laboratory studies have shown: too much salt can damage the stomach’s protective lining and make it easier for H. pylori to take hold. In Pete’s earlier research, adults with H. pylori were consuming an average of 3,765 milligrams of sodium per day, which is far above the recommended 2,300 milligrams. Over time, this combination of high sodium and chronic infection could contribute to the higher rates of stomach cancer seen in the Navajo Nation.

But Pete and her coauthors note that these findings can’t be separated from the larger social and historical forces shaping diet in the Navajo Nation. In the paper, they write that it’s essential to “shed light on the historical injustices and policies that have shaped the food choices and diet of the Navajo people.” Centuries of colonization, displacement, and economic inequity have disrupted traditional food systems, leaving many Navajo families with limited access to fresh, affordable foods. Today, access to fresh produce and affordable groceries is limited across much of the Navajo Nation. There are only about 15 grocery stores across the entire reservation. When your nearest store is hours away, it makes sense that people rely on shelf-stable foods that are easy to prepare.

In that light, the link between high-sodium dishes and infection risk isn’t just a nutritional issue, it’s a story about structural inequality and resilience. “This study can help inform public-health strategies that the tribe can use to tailor health education or design community-driven nutrition interventions,” Dr. Pete says. She envisions future research that looks at how food preparation, nutrient content, and even microbial changes in the gut interact with infection risk.

Fred Hutch/University of Washington/Seattle Children’s Cancer Consortium Member Drs. Dornell Pete, Johanna Lampe, Amanda Phipps, and Nina Salama contributed to this research.

This study was supported by the F99 National Institutes of Health/National Cancer Institute Fellowship Award, and Tribal Researchers’ Cancer Control Research Award.

Pete, D., Lampe, J. W., Liu, H., Salama, N. R., Wu, M. C., & Phipps, A. I. (2025). A Cross-Sectional Study of Dietary Patterns and Helicobacter pylori Infection Among American Indian Adults in the Southwest. Nutrition and Cancer, 77(9), 1043–1051.