When women undergo radiation, chemotherapy, and surgery for breast cancer treatment, their immune systems take a significant hit. This not only increases their risk of infection but also reduces their body's ability to eliminate cancer cells. According to a Czech study published in Immunotherapy in 2021, oyster mushroom supplementation offers a solution.

Study
Oncologists at Charles University in Prague divided 195 women with non-metastatic and hormone-sensitive breast cancer into two groups. For 15 months, 146 women received standard treatment, while 49 women took a daily supplement containing oyster mushroom extract in addition to their standard treatment.

The supplement is marketed as Neomun. The manufacturer of Neomun did not contribute to the study.

It contains a type of beta-glucan, which the company behind Neomun has named pleuran. In animal studies, pleuran increases the chance of survival after infection with dangerous bacteria. In human research, pleuran reduces the risk of viral infections. Pleuran apparently activates the immune system.

The researchers developed a schedule in which the women in the experimental group received alternating lower and higher doses of pleuran. This schedule is shown below. The researchers likely attempted to prevent tolerance and immune system exhaustion.

Using a publication on the extraction procedure for pleuran, [Molecules. July 2019;24(15):2740.] we converted the doses to fresh oyster mushrooms with a bit of guesswork.

Click on the table for a larger version.

Results
In the control group, the populations of some immune cell types declined at certain time points. In the experimental group, the populations remained stable or even improved.

CD8+ cytotoxic T cells, NK cells, and CD4+ Th1 cells are particularly relevant for slowing cancer. Pleuran also stimulated these three immune cell types.

CD8+ cytotoxic T cells can recognize and destroy cancer cells. They are currently also playing a key role in combating SARS-CoV-2 in vaccinated individuals.

NK cells ensure early, nonspecific elimination of tumor cells. NK cells currently also play a key role in combating SARS-CoV-2 in people who have not been vaccinated against SARS-CoV-2.

CD4+ Th1 cells support CD8+ and NK cells by releasing cytokines such as interferon-gamma and interleukin-2. Interferon-gamma and interleukin-2 stimulate immune cells to attack tumor cells. CD4+ Th1 cells currently still play a role in combating SARS-CoV-2 in vaccinated individuals.