Cholera is a severe bacterial infection that can be fatal without prompt treatment, particularly in regions with limited access to clean water. New laboratory research suggests that diet may influence how the cholera bacterium behaves in the gut, though the findings are early and based on animal models.
In a study published in Cell Host & Microbe, researchers at the University of California, Riverside examined whether different diets affected the ability of Vibrio cholerae to colonize the gut. Using a mouse model of infection, the team found that diets high in certain proteins reduced bacterial colonization compared with balanced, high-fat or high-carbohydrate diets.
“I wasn’t surprised that diet could affect the health of someone infected with the bacteria,” said Ansel Hsiao, an associate professor of microbiology and plant pathology at UC Riverside and the study’s senior author. “But the magnitude of the effect surprised me.”
The strongest effects were seen with diets rich in casein, a protein found in milk and cheese, and wheat gluten. According to the researchers, mice fed these diets showed dramatically lower levels of cholera bacteria in the gut.
“We saw up to 100-fold differences in the amount of cholera colonization as a function of diet alone,” Hsiao said.
To understand why, the researchers looked at how diet altered interactions between cholera bacteria and the existing gut microbiome. They found that casein and wheat gluten suppressed a structure on the bacterium’s surface known as the type 6 secretion system, which cholera uses to inject toxins and outcompete other microbes. When this system was dampened, Vibrio cholerae had more difficulty establishing itself in the gut.
“The high-protein diet had one of the strongest anti-cholera effects compared to a balanced diet,” Hsiao said. “And not all proteins are the same.”
The researchers stress that these findings do not suggest diet can prevent or cure cholera in people. Cholera remains a medical emergency that requires rehydration therapy and, in some cases, antibiotics. The study was conducted in mice under controlled laboratory conditions, and human biology, behavior and exposure risks are far more complex.
“Dietary strategies won’t generate antibiotic resistance in the same way a drug might,” Hsiao said, but he emphasized that dietary approaches would be considered supportive at most, not replacements for established public health measures.
Cholera continues to pose a threat in parts of the world where clean water and sanitation infrastructure are limited. While antibiotics can shorten the duration of illness, they do not neutralize the toxins produced by the bacteria, and overuse raises concerns about resistance. The researchers suggest that understanding how diet shapes interactions between pathogens and the gut microbiome could eventually inform complementary strategies to reduce disease severity.
Although Hsiao expects that diet could influence human infections in similar ways, he cautioned that more research is needed. Future studies are planned to test whether these effects appear in human microbiomes and whether similar mechanisms apply to other infectious bacteria.
“Some diets will be more successful than others,” Hsiao said. “The more we can improve peoples’ diets, the more we may be able to protect people from succumbing to disease.”
The study was supported by grants from the National Institutes of Health.