High-Protein Diets Found to Reduce Cholera Infection in New Study

A study from the University of California, Riverside, suggests that diets rich in certain proteins may significantly weaken cholera’s ability to infect the gut. Cholera, a bacterial disease that causes severe diarrhea and can be deadly if untreated, appears to be less effective at colonizing the intestines when the diet includes certain types of protein.

The research, published in Cell Host and Microbe, found that casein, the main protein in milk and cheese, and wheat gluten, made a difference in the amount of cholera bacteria able to infect the gut. “I wasn’t surprised that diet could affect the health of someone infected with the bacteria. But the magnitude of the effect surprised me,” said Ansel Hsiao, senior author of the study. According to Hsiao, the team observed “up to 100-fold differences in the amount of cholera colonization as a function of diet alone.”

The researchers designed experiments to determine how different types of diets—high in protein, fat, or carbohydrates—would impact cholera’s ability to establish itself in the gut of infected mice. High-fat diets did little to limit infection, and carbohydrate-rich diets only provided minimal benefit. In contrast, casein- and gluten-based diets markedly reduced colonization. “The high-protein diet had one of the strongest anti-cholera effects compared to a balanced diet. And not all proteins are the same,” Hsiao noted.

Further investigation showed that these proteins suppress the type 6 secretion system (T6SS), a microscopic syringe-like structure cholera bacteria use to inject toxins into host and neighboring cells. By weakening this mechanism, the pathogens lose their competitive advantage in the gut, limiting their growth and toxin production.

Cholera continues to threaten areas in Asia and Sub-Saharan Africa where clean water is scarce. Current treatments focus on rehydration, while antibiotics can shorten sickness but often fail to neutralize residual toxins. Hsiao cautioned that antibiotic use also carries the risk of fostering drug-resistant bacteria. “Dietary strategies won’t generate antibiotic resistance in the same way a drug might,” he said.

Hsiao emphasized that food-based strategies could serve as an accessible public health measure. “Wheat gluten and casein are recognized as safe in a way a microbe is not, in a regulatory sense, so this is an easier way to protect public health,” he explained. Although the study was conducted in mice, Hsiao expects similar results in humans and hopes to extend future research to other infectious bacteria.