Yeast Supplement May Boost Cancer-Fighting Immunity, Mouse Study Finds

Researchers at Trinity College Dublin and University College Dublin (UCD) have found that a yeast-based dietary supplement strengthened cancer-fighting immune cells in obese mice, according to a study published in the journal Cell Reports.

The study, led by Frederick Sheedy, associate professor in immunology at Trinity's School of Biochemistry and Immunology, and Helen Roche, professor in nutrigenomics at the UCD School of Public Health, Physiotherapy and Sports Science and director of the UCD Conway Institute, fed mice a standard or high-fat diet supplemented with yeast beta-glucan for 4 to 12 weeks. The mice's immune systems were then challenged with colorectal, skin and breast cancer cells.

The researchers found that yeast beta-glucan changed how immune cells developed in the bone marrow, producing stronger, longer-lasting anti-tumor immune responses, a process known as trained immunity. Roche said this is the first demonstration that dietary delivery of yeast beta-glucan is sufficient to induce trained immunity through reprogramming of bone marrow stem cells; earlier studies had achieved similar effects only through injections.

Obesity can disrupt immune function, making it harder for the body to respond to tumors, and these effects can persist even after weight loss. In the mouse experiments, the supplement helped restore anti-tumor immune activity in obese mice and reversed immune memory problems that remained after weight loss.

The yeast beta-glucan used in the study, Wellmune, made by Kerry Group, is already sold as a food-grade dietary supplement, which researchers say could allow relatively rapid clinical testing in people.