By Morgan Nwanguma
A simple yeast-based dietary supplement is likely to aid the restoration of the immune system’s capacity to combat cancer, going by new study in mice.
Scientists from Trinity College Dublin and University College Dublin (UCD) found that yeast beta-glucan can reprogramme early immune cells in the bone marrow, strengthening and prolonging anti-cancer immune responses. The effects were observed against colorectal, skin and breast cancer cells.
The findings, published in Cell Reports, could offer a new approach to addressing immune dysfunction associated with obesity.
Training the Immune System Through Diet
The research team, led by Frederick Sheedy, Associate Professor of Immunology at Trinity College Dublin, and Helen Roche, Professor of Nutrigenomics at UCD, investigated whether yeast beta-glucan could create a lasting form of immune training.
In the experiments, mice were fed either a standard or high-fat diet supplemented with yeast beta-glucan for four to 12 weeks. The animals were then exposed to different types of cancer cells to test how effectively their immune systems responded.
Researchers also examined whether the supplement could overcome immune dysfunction caused by obesity and whether its effects remained after the mice lost weight.
Dr. Anna Ledwith, a postdoctoral researcher in Professor Roche’s group and first author of the study, said the team wanted to determine whether a common dietary supplement could reprogramme early-stage immune cells in the bone marrow and produce stronger, longer-lasting anti-tumour responses.
The researchers found that consuming yeast beta-glucan altered the development of immune cells in the bone marrow, effectively creating a form of “trained immunity.” This type of immune memory allows innate immune cells to respond more strongly to subsequent challenges.
Professor Roche said the study is the first to demonstrate that yeast beta-glucan delivered through the diet can produce this effect by reprogramming bone marrow stem cells. Earlier research had produced similar immune-training effects through injections rather than dietary consumption.
Reversing Immune Dysfunction Linked to Obesity
Obesity can significantly alter immune function and make it harder for the body to respond effectively to infections and tumours. Some of these changes can persist even after weight loss, creating a long-term challenge for immune health.
In the mouse experiments, yeast beta-glucan helped restore anti-tumour innate immune responses in obese animals. It also reversed defects in immune memory that remained after the animals lost weight.
These findings are particularly significant because obesity affects immune function in ways that may not immediately disappear when body weight is reduced.
The researchers suggest that dietary approaches capable of restoring immune activity could eventually complement existing strategies for treating cancer and other conditions involving impaired immunity.
Potential for Future Cancer Research
Yeast beta-glucan is already available as a food-grade dietary supplement and has an established safety record, making it a practical candidate for further investigation.
The specific beta-glucan used in the study, Wellmune™, is commercially available and was supplied by Kerry Group. According to Professor Sheedy, its existing food-grade status could help facilitate clinical studies.
“This research paves the way for dietary intervention studies” in people with obesity, chronic infections and other forms of impaired immunity, Sheedy said.
The researchers also believe that, if the effects are confirmed in humans, yeast beta-glucan could potentially be used alongside established cancer treatments such as chemotherapy and immunotherapy. It may also have implications for vaccine responses and protection against infection.
However, the findings so far come from experiments in mice. Human studies will be needed to determine whether dietary yeast beta-glucan can produce the same immune benefits in people.
For now, the research provides evidence that a relatively simple dietary intervention may be capable of reshaping the immune system and restoring some of its cancer-fighting activity, particularly in the context of obesity.
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