Researchers Find Yeast-Based Supplement Strengthens Cancer-Fighting Immune Cells

Could a simple yeast-based food supplement help the immune system fight cancer? New research suggests it might one day become part of the answer.

Researchers from Trinity College Dublin (TCD) and University College Dublin (UCD) have found that a yeast-based dietary supplement can strengthen the body's cancer-fighting immune cells in obese mice. The findings, published in Cell Reports, suggest the supplement could become a safe and natural way to support cancer immunity.

The study focused on yeast beta-glucan, a naturally occurring fiber already available as a food supplement. Scientists wanted to see whether it could "train" immune cells in the bone marrow to mount stronger and longer-lasting responses against cancer.

For the study, mice were fed either a standard or high-fat diet supplemented with yeast beta-glucan for 4 to 12 weeks. Researchers then exposed the animals to colorectal, breast, and skin cancer cells to evaluate how well their immune systems responded.

The results showed that the supplement reprogrammed early-stage immune cells in the bone marrow, helping them develop into more effective cancer-fighting cells. Importantly, it also reversed immune dysfunction caused by obesity, which often weakens the body's ability to fight tumors.

Researchers found that these protective immune effects persisted even after weight loss, addressing a long-standing challenge because obesity-related immune defects often remain despite losing weight.

The team says this is the first study to show that consuming yeast beta-glucan through food can trigger this type of "trained immunity." Previous studies required injections to achieve similar effects.

While the findings are currently limited to animal studies, the researchers say the supplement could eventually complement existing cancer treatments such as chemotherapy and immunotherapy, while also improving vaccine responses and resistance to infections in people with weakened immune systems.

REFERENCE: Ledwith, A. E., et al. (2026). Yeast β-glucan supplementation supports immunometabolic anti-tumor responses and reverses obesity-induced dysfunction via trained hematopoiesis. Cell Reports. DOI: 10.1016/j.celrep.2026.117648.