The presence of certain intestinal bacteria types may improve the efficacy of alkylating chemotherapy agents such as cyclophosphamide, according to the results of a new study published in Immunity.

Researchers identified two strains of intestinal bacteria that acted as oncomicrobiotics, or immunogenic commensals that influence the cancer equilibrium in a person’s body. They evaluated T cell activity in 38 patients with lung or ovarian cancer and found that Enterococcus hirae and Barnesiella intestinihominis activated T cells, increasing the efficacy of alkylating chemotherapy agents. Patients with chemotherapy-resistant cancers also were found to have longer progression-free survival if the bacteria were present and initiated an immune response.

The researchers recommended that future studies evaluate oncomicrobiotics as a component of cancer treatments.