A microbiome therapeutic composed of a single-strain bacterium, isolated from the gut of healthy donors, with potential anti-tumor and immunomodulating activities. Upon oral administration, the metabolites of GEN-001 may activate dendritic cells and macrophages in the gut and increase the expression of the cytokines interleukin-7 (IL-7) and interleukin-15 (IL-15), which stimulates the proliferation of natural killer (NK) cells and memory CD8+ T-cells. The memory T-cells enhance the secretion of the cytokine interferon-gamma (IFN-g), which further potentiates the immune response against tumor cells. This may increase tumor cell killing and decrease tumor cell proliferation. GEN-001 may improve therapeutic responses to other therapies, such as anti-PD-1 therapy.