The goal of this clinical trial is to learn if beta-glucan (a dietary fiber) improves the function of the immune system in adults. It will also tell the investigators if combining beta-glucan with single bouts of exercise provides additional benefit. The main questions it aims to answer are:
1. Does beta-glucan change the ability of immune cells to recognize cancer cells?
2. Does exercise change the type of immune cells in the blood? Researchers will compare beta-glucan to a placebo (a look-alike substance with no effect) to see if beta-glucan could improve immune function against cancer.
Participants will:
1. Take beta-glucan or a placebo daily for 4 weeks.
2. Visit the laboratory for three exercise tests.
3. Provide blood samples so researchers can study immune system cells.