Abstract: Disclosed are improved methods for the treatment of diseases, disorders and conditions, such as cancer, using cell populations treated with a urolithin or urolithins, specifically urolithin-treated T-cell populations, for example, by enhancing the immune response comprising enhancement of antigen presentation and/or through enhancement of the expansion of T memory stem cells. Furthermore, disclosed are methods for overcoming or reversal of T-cell dysfunction to help treat diseases, such as cancer. More specifically, for example, disclosed are methods for overcoming of T-cell exhaustion. Also disclosed are cell populations enriched in T-memory stem cells.