Researchers at the University of California, Riverside have discovered that diets high in casein from dairy and wheat gluten can slash cholera bacteria colonization in the gut by up to 100 times. The findings, from mouse studies, show these proteins disrupt a key bacterial weapon. Ansel Hsiao, the study's senior author, highlighted the surprising magnitude of the effect.
A new study led by Ansel Hsiao, an associate professor of microbiology and plant pathology at the University of California, Riverside, reveals how specific proteins in the diet can combat Vibrio cholerae, the bacterium behind cholera. Cholera causes severe diarrhea and can be fatal without prompt treatment, remaining a threat in areas with poor sanitation like parts of Asia and sub-Saharan Africa. The research, published in Cell Host & Microbe, tested various diets on infected mice: high-fat ones had minimal impact, while high-carbohydrate diets provided only slight protection. Diets rich in casein—the main protein in milk and cheese—and wheat gluten nearly eliminated bacterial colonization in the gut. Hsiao noted, 'I wasn't surprised that diet could affect the health of someone infected with the bacteria. But the magnitude of the effect surprised me.' He added, 'We saw up to 100-fold differences in the amount of cholera colonization as a function of diet alone.' The proteins work by suppressing the bacteria's type 6 secretion system (T6SS), a syringe-like structure used to inject toxins and outcompete other gut microbes. Without it, cholera cannot dominate the intestinal environment. Hsiao emphasized the potential as a low-cost alternative to antibiotics, which risk fostering resistance. 'Dietary strategies won't generate antibiotic resistance in the same way a drug might,' he said. The team plans further research on human microbiomes and other pathogens, with Hsiao suggesting broader protective benefits from improved diets.